Organisers estimate that more than 60,000 people will visit the event over the next two days.
Highlights of the first day include a fly past at 3pm by a Dakota from the Battle of Britain Memorial Flight and a visit by cricketer Alec Stewart.
Thousands of people are expected to visit the Lincoln Showground today despite heavy rain.
Facts and figures about one of the Midlands biggest agricultural shows, the Lincolnshire Show.
The 128th Lincolnshire Show has begun. Over the next two days more than 60,000 people are expected at the Lincoln Showground.