The effects of trifluralin and pendimethalin concentration and treatment time duration on the cluster buds of wild Lilium sargentiae(2n=2x=24) in vitro were investigated.With sterile water (CK) and colchicine as control,we soaked L.sargentiae adventitious shoots in different concentration (100,200,300 μmol/L) herbicide (trifluralin,pendimethalin) solutions for 12 h,24 h and 36h,respectively.The chromosome number and stomata guard cell of leaf hypodermis and morphology characteristics of leaf were studied.The results indicated that the treatment of materials in pendimethalin solution at 300 μmol/L for 36 h lead mutation rate of 30.0%,200 μmol/L trifluralin soaked 36 h,mutation rate of 32.2%.The two kinds of mutagens treatment induced mutation and survival rates were not significant.Mutants identified by cytology to find the two kinds of mutagens treatment are able to induced mutation.Compared with colchicine,the mutagen processing time is short,material mortality is low,mutation rate is high,damage to humans and animals is less and cost is low.Compared with the diploid plants,in the size of stomata in tetraploid plants significantly increased and stomatal density decreased significantly.The study considers the herbicide pendimethalin and trifluralin can be used as a substitute of colchicine to induce polyploidy,and the stomatal size can be used as an effective indicator for polyploidy initial rapid detection.