Russell Hobby, general secretary of the National Association of Head Teachers (NAHT), said the results were "excellent news".
"It shows the hard work that's going on in the system and has been going on for some years."
He said the majority of primaries will not be academies, which shows that schools can improve "no matter what their status".
Data released today shows England's best and worst ranking primary schools based on performance in this summer's national curriculum tests.
Read the full storyThis year's top-ranking school, for the second year running, was Newton Farm Nursery, Infant and Junior in Harrow.
It gained the highest average points score at 34.1.
Pupils sitting the National Curriculum tests are given a set number of points for the level they achieve.
Level 2 or below is worth 15 points, Level 3 is worth 21 points, Level 4 is worth 27 points, Level 5 is worth 33 points, Level 6 is worth 39 points.
Each pupil's points for English and maths are added up and divided by the number of tests taken to give a school's average points score.
Schools with less than 30 pupils are not included.
A Department of Education spokesman said that the aim of their floor target was to boost standards and "end years of chronic under-performance."
Today's figures demonstrate that schools have responded to the challenge.
The floor standards we introduced were tougher and have improved performance.
Heads, teachers and pupils deserve credit for meeting the challenge head on.
The latest league tables show how more than 15,000 primary schools performed in national curriculum tests - known as SATs - in English (reading and writing) and maths.
Under the Government's current target, schools are considered failing if fewer than 60% of 11-year-olds reach the expected standard - Level 4 - in English and maths SATs tests, and fewer youngsters make two levels of progress in these subjects than the national average.
The national average for English progress this year is 92%, and for maths it is 90%.
Schools that fail to reach this threshold are at risk of being closed and turned into academies.
The latest figures show that of the 521 schools which are below the bar, 45 have already closed, with 37 becoming academies.
The number of primary schools failing to give pupils a good grounding in the three Rs has halved in the space of a year, official figures suggest.
In total, 521 schools in England are below the Government's floor target for primaries, according to an analysis of data used to create new primary school league tables.
Last year, 1,310 schools were below the threshold.
The results show that schools have "responded to the challenge" that was given to them, the Department for Education (DfE) said.
David Cameron has talked up the "exciting" changes in the state school system and said he wanted his own children to benefit from the "massive innovations".
The Prime Minister today launched an initiative to turn the UK's 400 weakest primary schools into academies.
Speaking at a PM Direct event, he said:
I would like them [my children] to go to state schools, that's my intention, and I think what's happening in the state school system is really exciting.
Instead of having a set of comprehensive schools we've introduced an element of choice and competition which is leading to massive innovation. As well as academies we've also introduced free schools.
So what we're seeing in the state sector is something that we should have seen years ago which is the flowering of more choice, more competition, more diversity and crucially higher standards.
I want my children to be part of that and I'm very heartened by what is happening.
Stephen Twigg, Labour’s shadow education secretary, has challenged the government to make “sustainable” improvements to schools that go beyond the new academy drive announced today.
He said:
The original focus of Labour’s academy programme was on under-performing schools – but unlike this Government, we worked with schools to ensure improvements were sustainable.
Changing the type of school is not enough – we need a programme to raise the quality of teaching and school leadership, which is what makes the most difference. But under this Government, we’ve seen 10,000 teachers leave the profession.
We also need a One Nation education plan – getting strong schools to support weaker schools, so that no school is left behind. That can be achieved in many ways, including through federations, clusters of schools and co-operative trusts – academies are not the only answer.
Prime minister David Cameron hosted a meeting of the Cabinet at an academy school in Bristol today.
The meeting at John Cabot Academy - described by Downing Street as one of England’s leading academies - came on the day Cameron announced plans to turn the UK's 400 weakest primary schools into academies.
Christine Blower, general secretary of the National Union of Teachers, has described the move as ‘irresponsible’.
There are now 2,456 academies, and further 823 in the pipeline. Of the new academies, 333 were formerly failing primary or secondary schools.
Christine Blower, general secretary of the National Union of Teachers (NUT), has described the move to turn 400 primary schools into academies as ‘irresponsible’.
She said:
There is no evidence to show that academy status in primary schools will bring any educational benefits.
Despite this the coalition government is pressing ahead regardless, removing schools from their local authority and handing them over to unelected sponsors.
It is quite extraordinary that at a time of such huge spending cuts the Prime Minister is announcing that he is happy to spend £10 million to find sponsors for this project.
This is such irresponsible and rash behaviour from a coalition whose motivation appears ever clearer to be the privatisation of our education system.
