To evaluate the toxic effects of different proportions of Coptidis Rhizoma and Tetradium ruticarpum extracts on Caenorhabditis elegans.Methods:Coptidis Rhizoma was used as model organism and preparing water extracts of Coptidis Rhizoma and Tetradium ruticarpum in different proportions。Assessing the effects of various water extracts on the survival rate，body length，head and tail swinging frequency and body bending frequency of C.elegans.The number of 30 C.elegans were observed and counted at the same time every day,and the death time of the last C.elegan was taken as the maximum life span.The body length of 40 C.elegans was measured by Image J software after C.elegans were killed in the oven and photographed.Counting the number of head and tail swinging frequency of 30 C.elegans in 1min(from one side to the other and back again) and the number of body bending frequency of 30 C.elegans in 20s(the movement of nematodes relative to one wavelength along the long axis of the nematode was taken as one body bending) to evaluate the effects on motor behavior of C.elegans.Results:Compared with the group of Coptidis Rhizoma，as the relative proportion of Tetradium ruticarpum increasing,the mortality rate of C elegans was significantly decreased(P<0.01).The body length was significantly reduced(P<0.01).In the aspect of locomotion behavior,the addition of Tetradium ruticarpum can't significantly reduces the frequency of head swing and body flexion of C.elegans.Conclusion:To a certain degree Tetradium ruticarpum can reduce the toxicity of Coptidis Rhizoma to C elegans,extending its life.In terms of growth and nerves，it has less affection.And the research provided a new method for the study of Coptidis Rhizoma and Tetradium ruticarpum in pairing and concoction.