We have examined the induction of HL-60 cell differentiation by treatment of 2-chloromethyl-1-dihydroxyphosphinyl pyrrolidine(2C-1DPP), which is derivative of piperidine and pyrrolidine by ${alpha}-phosphoramidoakylation$ reaction. It was observed that HL-60 cell proliferation was dose- and time-dependently inhibited by treatment with 2C-1DPP. 2C-1DPP treatment caused a significant change in NBT reduction and enhanced ATRA-induced NBT reduction. Treatment of 2C-1DPP to HL-60 cells increased only CD11b expression in the cells, and also increased markedly G0/G1 stage arrest of HL-60 cells. These results can suggest that 2C-1DPP induced the differentiation of HL-60 cells to granulocytes lineage and enhanced ATRA-induced differentiation. Moreover, DNA expression levels of p27 were up-regulated during 2C-1DPP-dependent HL-60 cell differentiation. Our results suggest that 2C-1DPP have potential as a therapeutic agent in human leukemia.