Size-tunable ZnS nanocrystals were obtained by electron sputtering. Almost sputtered nanocrystals were spherical and well-dispersed. The sizes of deposited ZnS nanocrystals appeared a good gradient distribution according to their distance away from the sputtering target. These nanocrystals had gradual changes in diameter from about 1 to 15 nm. This research may afford a simple and efficient method to prepare well-dispersed semiconductor nanocrystals in a small size range.