Female golfers will play for a $US1 million first prize at this week's US Women's Open, the first time a tournament winner will get a seven figure payout.
The total purse will be $US5.5 million, up $500,000 from last year.
That is less than half the record $12.5 million on offer at the men's US Open at Pebble Beach in two weeks' time, though the $500,000 increase from last year is the same for both sexes.
American world number eight Lexi Thompson said the purse announcement had been greeted positively by the players.
"I can definitely say I think the players are very excited about the news, and hopefully we can just keep on improving," Thompson said.
"I think it's amazing news. And I think it strikes us as the women's game is growing so much. I think it's very well-deserved."
Total prize money on the LPGA Tour this year will amount to about $70 million, about a fifth of what the men play for.
Commissioner Mike Whan said it was unrealistic to expect parity.
"The difference in purses is the difference in total viewership," he said in an interview with Reuters in January, referring to television ratings.