Somerset have given new contracts to Craig Meschede, Johann Myburgh, Tom Abell and Jack Leach.
Seamer Meschede, 22, graduated through the Taunton club's academy set-up, along with spinner Leach, 23, and opener Abell, 20.
South African all-rounder Myburgh, 33, has been retained after initially signing for the 2014 season.
Meanwhile, Somerset have confirmed that all-rounder James Burke is leaving to join Surrey for next term.
Chief executive Guy Lavender said: "We are sorry to be losing James, but wish him well for the future with his new club.
"We are delighted that Tom Abell, Jack Leach, Craig Meschede and Johann Myburgh have signed new contracts with Somerset.
"The three youngsters have all come through our own youth system and joined the club from the academy, while Johann has proved himself to be a valuable asset and a great clubman during this year."