Yorkshire have handed young quartet Will Rhodes, Jonathan Tattersall, Ben Coad and Oliver Robinson full-time junior deals.
All-rounder Rhodes and top-order batsman Tattersall, both 18, made their first-team debuts in 2013 and are currently in the United Arab Emirates with England Under-19s for the Tri-series against the hosts and Pakistan.
Seamer Coad, 19, and 20-year-old all-rounder Robinson still await their progression from the second XI but have been rewarded with new deals.
Rhodes appeared in seven Yorkshire Bank 40 and two Friends Life t20 fixtures while Tattersall made his List A debut against Glamorgan at Headingley in August.
Yorkshire director of cricket Martyn Moxon said: “The junior pro contract bridges the gap between academy and second XI cricket.
“We have some quality players coming through the grades and the four lads we have rewarded deserve to be recognised.
“They have had a taste of first team cricket last season and I look forward to seeing them flourish over the year ahead. They all have the potential of making a big impact in the game and being part of our plans for many years to come.”
The four players join seam bowler James Wainman as Yorkshire’s five junior professionals.