With the method of stability water tests, we examined the acute toxicity and their pairwise joint toxicity of metolachlor, kresoxim-methyl and prochloraz-manganese chloride complex to Bufo gargarizans tadpoles. Our results showed that under acute toxicity alone treatments the median lethal concentrations (LC50) of metolachlor, Kresoxim-methyl and prochloraz-manganese chloride complex examined in 24h, 48h and 72h were 29.81, 28.81, 25.83 mg/L; 1.72, 1.46, 1.41 mg/L and 7.43, 3.75, 3.22 mg/L respetively, with their corresponding safety concentration (SC) of 8.07, 0.32 and 0.29 mg/L, respetively. The toxicology of metolachlor were moderately toxic, whereas both Kresoxim-methyl and prochloraz-manganese chloride complex were highly toxic. Under pairwise joint toxicity treatments, we found that the effects of the combination of metolachlor/kresoxim-methyl and metolachlor/prochloraz-manganese chloride complex were moderately toxic, while the combination of Kresoxim-methyl and prochloraz-manganese chloride complex was highly toxic. The LC50 values examined in 24h, 48h and 72h were 18.41, 15.69 and 13.38 mg/L for metolachlor/kresoxim-methyl group, with corresponding values of 15.56, 10.45 and 8.11 mg/L for metolachlor/prochloraz-manganese chloride complex group, 4.17, 2.84 and 2.00 mg/L for kresoxim-methyl/prochloraz-manganese chloride complex group, respetively, and their safe concentration were 3.42, 1.41 and 0.40mg/L. For toxic evaluations of pairwise combinations of the three pesticides, we found that the treatments conducted in metolachlor/ kresoxim-methyl group and kresoxim-methyl /prochloraz-manganese chloride complex at 48h showed antagonistic, the remain treatments showed synergistic. Combined and compared the data previously published, we found that the tadpoles of Bufo gargarizans were highly sensitive to various pollutants. We hoped these results should provide us some valuable scientific references for further investigation of toxicity in anuran species.