Sussex captain Michael Yardy will lead the side one more time in the Friends Life t20 finals day next month.
The 31-year-old has captained the side since 2009, during which time the Sharks have won trophies in Twenty20 and 40-over cricket, as well as Division Two of the championship.
But he has decided to hand over the reins to Ed Joyce, starting in the LV= County Championship match against Worcestershire starting on Wednesday.
Yardy continued in the role even after revealing he was suffering from depression, which forced him to return home from England's World Cup campaign last March.
"I have decided to step down as captain in order to concentrate on my own game," he said.
"There are many things I still wish to achieve as a player which will also hopefully help contribute to the team winning more silverware.
"I would like to say a massive thank you to everyone for all the effort they have put in over my time as captain and I look forward to leading the team at t20 Finals Day."
Sussex's professional cricket manager Mark Robinson said: "Michael has been an incredibly dedicated captain who has worked tirelessly and selflessly for the good of the club.
"Ed Joyce will now take over the captaincy duties until the end of the season with the same responsibilities as Michael had, including the final say on selection."