Surrey teenagers Dominic Sibley and Tom Curran have signed new deals.
The pair, who are due to take their A-Level exams in the summer, will join the playing staff full-time once their school education is complete.
South Africa-born fast bowler Curran, 18, featured in five YB40 matches, taking 5-34 against Scotland.
Batsman Sibley, 18, became the youngest double-centurion in County Championship history when he struck 242 against Yorkshire at The Oval in September.
The total, which came off 536 balls and included 24 fours and two sixes, meant Sibley became Surrey's youngest-ever centurion, the second-youngest player to score a first-class century in England, and the 13th youngest first-class double-centurion in history.
Surrey director of cricket Alec Stewart said: "These are two highly promising young cricketers.
"We look to seeing them develop over the next few seasons."