Abstract: This paper is a study of, the rice-weed communities and the bioecological characteristic of rice-weeds in Bai Ge Zhuang of Hebei Province. The main life-forms of the weeds in rice fields are therophytes, and perennial grass. Though they grow luxuriantly and have strong reproductive ability, there is a weak stage in the life cycle of every species of weed. In this stage, the nutrition of the seeds or the under-ground organs are exhausted at all and their strong roots haven’t developed yet. This is the optimum stage to control the weeds. The weeds often mix with the rice to form a rice-weed community which has certain floristic composition, structure and physiognomy. As a rule different plant communities form in different ecological conditions. But some of the rice-weed communities which have widely ecological amplitude can distribute everywhere in China. There are also seasonal dynamic and regularity of succession of the rice-weed communities. Such process is effected not only by the weed’s biological characteristics, but also by environmental conditions and the artificial influence. Only when the developments of succession of communities are fully known, can the effective measures be taken to control the weeds in time.