Abstract: Objective To investigate the curative effect of acyclovir ointment on herpes labialis，to improve the cure rate and to reduce the duration of treatment. Methods In 105 cases of herpes labialis，randomly choosed 58 of them to be treated with acyclovir ointment，and the rest of 47 to be treated with cream of erythromycin. Compared the cure rates and the duration of treatment between these two groups. Results The group treated with acyclovir ointment：in 58 cases，55 of them were cured（94. 8% of total group），excellence was 3（5. 2%），positive and invalid were 0. The group treated with cream of erythromycin：in 47 cases，9 of them were cured（19. 1% of total group），excellence was 6（12. 8%），positive was 5（10. 6%）and invalid was 27（57. 4%）. Conclusion Compared with cream of erythromycin，acyclovir ointment is better for herpes labialis treatment. It′s easy to apply，and has a lighter side effect. It is worthy to be popularized.