[Objective] The propose was to study the joint toxicity effect and mechanism of two contamination as LAS and fentin acetate.[Method] In lab test,the single and joint toxicity of LAS(Sodium dodecyl benzene) and fentin acetate(triphenyl-acetic acid-tin) on Misgurnus angullicaudatus was observed by static biology test method and their joint toxicity was evaluated by using Marking additive index method.[Result] The single toxicity test showed that fentin acetate was of hypertoxin and the LAS of high toxin on M....