According to the 3year daily statistical data about nonoccupational CO poisoned patients from 16 firstaid centers over the eight districts in the central Beijing, the relationship between the number of CO poisoned patients and ground meteorological elements is analyzed. The results show that the number of CO poisoned patients was greater in the winter half year (from October to April). The mean occurrence rate of CO poisoning in January was 8.1 per 107, being the largest in a whole year. The mean of monthly CO poisoned patients had positive correlation with monthly sea level pressure and negative correlation with monthly extreme low temperature. The correlation coefficient between the mean of extreme low temperature of the past 9 days and the number of CO poisoned patients of the future 9 days is －0.7661. It is important for meteorological service to provide CO poisoning warning based on weather forecast.