Ecological effects of weeds on soil water and soil nutrient were studied in winter wheat. The results showed that weeds, in winter wheat farmland, raised soil water content, especially in 0~20 cm profile. Moreover, in 0~60 cm profile, the loss of available-N was the least and the total amount of available-P was increased (comparatively, other treatment's were decreased) and available-K increment was the maximum in WK(weeds keep) treatment. Furthermore, the total amount of nutrient(available-N,P and K) of WK treatment was the most in harvest period.