Tolerance test of dichlorvos on ornamental fish species which consist of Gourami fish, Redtailed black shark, Redfin shark, Fancy carp fish, Bala shark, Goldfish, Ballon fish, Swordtail fish. Sumatra barb fish and Guppy fish were experimented by static exposure for 96 hours. Seventy fish in each species were exposed to dichlorvos at concentration of 0, 0.1, 0.2 and 0.4 mg/L. Each fifty-liter tank contained 10 fish with duplication. Water quality was pH 7.20-8.41, hardness 102-119 mg/L, and alkalinity 90-95 mg/L., chlorine 0.01-0.03 mg/L, nitrite 0.20-0.39 mg./L. and ammonia 0.08-0.09 mg/L. The mortality rate of the Gourami fish at 0.2, 0.4 mg/L were 10, 30 percent respectively. The mortality rate of fancy carp at 0.1, 0.2, 0.4 mg/L were 5, 20 and 30 percent respectively. The mortality rate of ballon fish at 0.4 mg/L of dichlorvos was 5 percent. The mortality rate was not observed in other species even the control group. The result indicated that fancy carp was the lowest tolerance to dichlorvos when compared to the Gourami fish and balloon fish respectively.