In order to explore the developmental embryo morphology in vitro culture and design the most optimal embryo medium for Sebastes schlegeli, physiological saline as the main formula set as control group (first group) was respectively supplemented with 1% serum of S. schlegeli (second group), 1% homogenate of ovarian tissue of S. schlegeli (third group), 1% fetal bovine serum (fourth group), 1% serum of S. schlegeli and 1% homogenate of ovarian tissue of S. schlegeli (fifth group), which formed into five different media. High blastocyst stage and crystal stage were respectively set as the original embryonic phase, and then were placed in the above five different media. According to the observation and records, present study found that when the original embryonic stage was high blastocyst stage, although embryo in every group can develop to 16-sarcomere stage, developmental speed and duration greatly varied. The fifth group displayed fastest developmental speed for 60 h, the fourth groups show the worst performance for 67 h and the speeds of the rest of the groups were between the fourth group and fifth group; when the initial stage was crystal phase, the fifth had the fastest speed for 57 h and the highest hatching rate at 80%. The second possessed identical speed, but had lowest hatching ability for 40%. Research showed that, under the in vitro culture condition, it needed about 200 h to make fertilized eggs develop to newly hatched larvae and it was the fifth embryonic medium that made the embryo have fastest developmental speed in S. schlegeli.