Abstract: BACKGROUND ＆ AIM： To test the feasibility to use leukemic cell lines in the screening process for anticancerous drugs. MATERIAL AND METHODS：Human leukemic cell lines HL-60 and K562 were tested for their sensitivity to three known anticancerous drugs (Ara-c, DNR, Hom) and a new one (MTB). The drug sensitivity was assessed by four methods (survival cell count, 3H-TdR incorporation, 3H-UR incorporation and clone forming assay) and expressed in ED50. RESULTS: The curves of survival cell rate determined by the first three methods showed the sensitivity was well within the range of 10－2, approxi-mating to one another, while in the case of cloning method, the sensitivity was as high as 10－7. Besides , the survival cell rate of K562 was higher than that of HL-60. CONCLUSION：To use human leukemic cell lines as the target cell for anticancerous drug screening has the advantages that the laboratory procedures are relatively simple and the results are of better clinical significance.

Key words: human leukemic cell line, fluid quantitative culture, limiting dilution assay