Abstract: The morphological changes were observed and the effect of temperature on embryonic development of Macrobrachium rosenbergii was studied. The results showed that the embryonic development could be divided into eight stages，including fertilized egg stage，cleavage stage，blastula stage，gastrula stage，egg nauplius stage， egg metanauplius stage，protozoea stage and zoea stage. Within a certain temperature range，speed of embryonic development decreased with increase of temperature with optimum temperature around 30℃. At 30℃，the aperture ratio and hatching rate of larvae were the highest，and the cost was less. The regression equation of developmental temperature and development time was described as y=181.127-9.921 x+0.149 x2.