Abstract: Effects of wheat varieties on flixweed were studied in a field experiment. The result showed that flixweed biomass, leaf area index and seed Production growing with different varieties were different. Flixweed growing with wheat varieties in a strong competitive ability was poor, wheat grain yield was higher. This trend enhanced with higher density of winter wheat, When wheat varieties in stronger competitive ability were planted in a field where many flixweeds existed, wheat yield loss caused by flixweed infestation could decrease.

Key words: Pinus koraiensisdominated broad-leaved mixed forest, forest gap, mound top, microsite, microclimate.