Abstract: In order to control weedy rice effectively and make use of its stress-tolerance characteristics, the effect and competitive advantages of weedy rice on cultivated rice were analyzed, including field seedling emergence, tillering, growing environment, photosynthesis, material accumulation, nutrient absorption-utilization, yield formation and so on. Major stress tolerance characteristics of weedy rice which were formed along with the long-term adaptation to the ecological environment were summarized, such as deep seeding tolerance, low temperature tolerance, drought tolerance, saline-alkali tolerance, heavy metal tolerance and disease resistance. It showed important significance to excavate the genetic resources of superior characteristics in weedy rice for future applications of rice genetic modification. Moreover, It had referential significance to study the allelopathy of weedy rice for chemical synthesis of botanical herbicide.