The post embryonic morphological development of Hexagrammos otakii was observed, measured and recorded by a micro cinematographic system to explore the morphological development characteristics in different stages of larval and juvenile fish. Newly hatched larvae, 6.18±0.50 mm long and depending entirely on the egg contained energy, were nursed at 16.0±0.5℃, salinity 31, illumination 500～1 000 lx. At 3 dph (days post hatching), 7.55±0.27mm in length, with the rudimental yolk sac at abdomen, some larvae started feeding rotifers, and the development entered the exogenous feeding stage. After yolk was exhausted at 6 dph, the larvae started feeding Arternia nauplii. At 48 dph, the larvae started feeding compound feeds. The relationship between total length (TL) and days post hatching (D) for 0~7d，7~48d，and 48~80d fish was described as: TL(0～80) = -0.000 2D3 + 0.028 1D2 -0.155 7D + 7.376（R2 = 0.993 9）; TL（0～7）= 0.004 6D3 -0.057 2D2 + 0.383 1D + 6.175 1（R2 = 0.997 1）; TL（7～48）= 0.000 5D3-0.026 7D2 + 0.931D + 2.269（R2 = 0.997 3）; TL（48～80）= -0.0001D3 + 0.018 7D2-0.204 5D +24.646（R2 = 0.999 8）.