Abstract: Aiming to confirm the control effects of 15% metazosulfuron·penoxsulam dispersible oil suspending agent（OD） against annual weeds and safety in transplant rice field, field pharmacodynamic experiments were carried out by the stem and leaf spray methods. The results showed that the recommended dosage of 15% metazosulfuron·penoxsulam OD in field were 67.50~112.50 g （a.i.）/hm². At 30 day after spraying treatment, the weeds control effects on quantity and on fresh weight were 98.39% and 98.83%, respectively. Within the range of recommended dose,15% metazosulfuron·penoxsulam OD could effectively control weeds in transplant paddy field, and it was safety to rice.

Key words: metazosulfuron, penoxsulam, efficacy, safety