Abstract: In order to improve the artificial breeding technology of the speckled snowmark clownfish (Amphiprion sp.), we observed the breeding habits, embryonic development and post-embryonic development under artificial simulated natural conditions. The results show that the fertilized eggs were 1.9−2.1 mm in long diameter and 0.93−0.95 mm in short diameter. The embryonic development mainly went through sperm-egg stage, embryonic disc stage, oogenesis stage, blastocyst stage, protointestinal stage, neuroembryonic stage, organ formation stage and hatching stage. At the water temperature of (27±0.5) ℃, it took approximately 197 h for the fertilized egg to hatch out of the membrane. The newly hatched larvae had a total length of (4.415±0.412) mm, a transparent body, obvious fin membranes, and only a small portion of the yolk sac remained, which had been opened for feeding. Larval stage: At 9 days after hatching DAH, body length of (6.813±0.835) mm), the fin membrane disappeared and the fins formed, and the banding on the head appeared. Juvenile stage: at 21 DAH Body length of (10.581±2.659 mm), accompanied by scale formation on the body, the differentiation of body colour and stripe banding started to appear. Young stage: 35 DAH Body length of (15.512±4.927) mm, four different strains with different body colour patterns were easily identified. In brief, as an artificially selected new variety, the most obvious feature during the post-embryonic development of speckled snowmark clownfish is formation and differentiation of body colour patterns such as stripe banding during juvenile stage.