Among more than 75 variants of microcystin(MC),microcystin-LR(MC-LR) is one of the most common toxins.In this study,the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied.C.elegans was treated with MC-LR at different concentrations ranging from 0.1 to 80 μg/L.The results showed that MC-LR could reduce lifespan,delay development,lengthen generation time,decrease brood size,suppress locomotion behavior,and decreases hsp-16-2-gfp expression.The endpoints of generation time,brood size,and percentage of the population expressing hsp-16-2-gfp were very sensitive to 1.0 μg/L of MC-LR,and would be more useful for the evaluation of MC-LR toxicity.Furthermore,the tissue-specific hsp-16-2-gfp expressions were investigated in MC-LR-exposed animals,and the nervous system and intestine were primarily affected by MC-LR.Therefore,the generation time,brood size,and hsp-16-2-gfp expression in C.elegans can be explored to serve as valuable endpoints for evaluating the potential toxicity from MC-LR exposure.