Ali moved to Worcestershire CCC for the 2007 season, and has gone on to become one of the first names on the teamsheet. During his career, he has scored eight First Class centuries.
Ali said, "When I first joined the Club many people told me what a fantastic place New Road is to play and they are right, so I am delighted to commit my long term future to the Club."
"The future for Worcestershire looks good and being a part of it excites me. I look forward to helping the Club progress back to Division One and win some trophies."
More top news
A family who manufactured illegal guns and bullets for criminals in the West Midlands have been jailed for a total of 47 years.
The woman who left an abusive note on an ambulance that was treating her sick neighbour has been evicted from her home.
Two lorry drivers have been sentenced after a fatal motorway crash that killed eight people.