We compared the effects of different salinities, different temperatures, and caffeine on triploid induction of in terms of cleavage rate, D larval rate and triploid rate. The effects of intensity or concentration, duration of treatment, egg density, and induction time were also studied. After the zygotes were fertilized at 31℃ and salinity of 15, optimum results were obtained 15 min post fertilization after hyperosmotic shock in the salinity of 40 for 10 min treatment, with a zygote density of 1.0×10⁷ ind/L. Under these conditions, the cleavage rate was (39.60±2.14)%, D larval rate was (31.46±1.06)%, and triploid rate was (59.53±5.90)%. The induction time and duration of treatment obtained the same results as that of the high salinity treatment; however, the zygote density was 2.0×10⁷ ind/L and zygotes were induced by 10℃ seawater, with these conditions optimum at low temperature. Here, the cleavage rate was (21.00±4.90)%, D larval rate was (12.68±1.21)%, and triploid rate was (51.09±2.67)%. Additionally, spawn was fertilized at 31℃ and a salinity of 15 and, 15 min after fertilization, 2.0 g/L caffeine was added for a duration of 20 min at a zygote density of 1.0×10⁸ ind/L, which were the optimum conditions of triploid induction by caffeine. Under these conditions, the cleavage rate was (85.46±4.78)%, D larval rate was (71.79±3.92)%, and triploid rate was (56.36±2.07)%. At the optimum conditions, the efficiency of triploid induction in caffeine (0.405) was higher than that of the high salinity (0.187) and low temperature (0.065) treatments. In addition, the triploid rate of larvae induced by the high salinity or low temperature was greatly decreased and the survival rates were lower than those noted for caffeine treatment. Therefore, caffeine was more applicable for triploid induction of than the other two methods, i.e., high salinity and low temperature. This study provides basic knowledge and practical evidence for triploid induction of .