Study on allelopathy of soil aqueous extracts from different planting patterns on flax were tested by the methods of bioassay. The results showed: 1)Different treatment of soil aqueous extracts had different degrees inhibition on flax seed germination，and high concentration treatment was more effective than that of low concentration treatment.Inhibition effect ranked as flax continuous cropping>flaxwheat intercropping> abandoned>wheat continuous cropping,which means that flax continuous cropping produced more continuous cropping obstacle,and the toxic effect was obvious; 2)Different treatment of soil aqueous extracts had different degrees inhibition of shoot fresh weight，root fresh weight and root length on flax seedling growth，and in high concentration mainly inhibited shoot fresh weight,root fresh weight and root length，at low concentrations mainly inhibited root fresh weight and root length.The effects of flax continuous cropping and abandoned was greater than those of flax  wheat intercropping and wheat continuous cropping; 3)The inhibition synthesis effect(SE)of different soil aqueous extracts increased with the rising of concentration,but the treatment of high concentration treatment was less than that of the low concentration treatment in wheat continuous cropping,and comprehensive effect from large to small in turn was flax continuous cropping>abandoned>flax  wheat intercropping>wheat continuous cropping;4)Different planting patterns of soil obviously improved allelopathic effects of flax continuous cropping,and the effect ranked as wheat continuous cropping> flaxwheat intercropping>flax continuous cropping. In summary,flax continuous cropping obstacle occurred,rational crop rotation help to improve the flax allelochemicals accumulation caused by continuous cropping obstacle.