This experiment was conducted to study the effects of herbicides and their damages to lawn plant for the control of lawn weeds using pre-emergence granule herbicide at the two years old lawn field. The results obtained are summarized as follows. 1)Herbicidal damages to lawn grass were observed at the higher concentration than the recommended level in four herbicides used in this trial. The optimum dosages for the control of lawn weeds were 3-6g in Lasso, 3g in Machet, 8-24g in Simazine, and 4g in Trifluralin, respectively. 2)No herbicidal damages was observed in Simazine treatment, whereas Lasso and Machet treatment showed a little and severe herbicidal damages, respectively. The most severe damage was found in Trifluralin treatment, indicating that this herbicide is not suitable for the control of lawn weeds.