：Objective To clone differentiation-related genes of human leukemia K562 cells

and to study the mechanism of differentiation of K562 cells induced by matrine. Methods Differentially expressed genes between K562 cells and their matrine-treatment cells have been investigated by mRNA differential display technique. Results There were obvious differences in gene expression of K562 cells before and after matrine treatment. The expression of some genes was decreased or inhibited while that of other genes was active. Conclusion Matrine plays an important role in regulating the differentiation-related gene expression. The differentiation induced by matrine is a complex process with multiple genes involved.