Objective: To explore whether acycloguanosine (ACV) can inhibit the proliferation and induce the erythrodifferentiation of human myeloid leukemia K562 cells. Methods: K562 cells were cultured with ACV for 4 d to detect cellular changes. Results: When K562 cells grew in a medium containing ACV, the cellular growth and division were gradually suppressed, growth fraction decreased and further differentiation towards the cell producing hemoglobins was found. Conclusion: ACV can inhibit proliferation and induce erythrodifferentiation of K562 cells.