Objective: To investigate the effects of Ro13-7410on telomerase activity and cell cycle distribution.Methods: Telomerase activity of HL-60 cells induced by retinoid Ro13-7410 was detected by telomerase PCRELISA-kit. The cell cycle was analyzed by flow cytometry. Results: Telomerase activity declined gradually after 10-6 mol/L Ro13-7410 treatment, and the inhibition of telomerase activity at day 5 of treatment with Ro13-7410 was less effective than with Retinoid Acid (RA).DNA flow cytofluorimetric analysis revealed that Ro13-7410 caused partial cells arrest in the G2/M phase after 4-days treatment. Conclusion: Telomerase activity declined gradually and partial cells were arrested in the G2/M phase after Ro13-7410 treatment.