Abstract: Flatstalk Bulrush is a perennial, notorious weed which spreads over the paddy-rice fields and lowlands in the world. It has a distinct growth rhythm. Its sexual reproduction is more limited than vegetative propagation in relation to the growing season. Under the semi-sunshine condition, it cannot produce seeds, and its vegetative propogation is retarded.The stage of development of Flatstalk Bulrush is correlated to leaf age. The equation of linear regression of its regrowths can thus be predicted by the leaf age of main stalks as: Ŷa= –36.74+6.24x (1983), and Ŷa= –32.42+6.28x (1984) ; The equation of linear regression for predicting its tuber is. Ŷt= –67.97+l0.12x (1983) , and Ŷt= –33.91+ 8.04x (1984). The weed control with machine and man-power can suppress forming tuber and producing seeds but help its regrowths spread out.The occurrence and distribution of Flatstalk-Bulrush are correlated with cropping system. The emergence of its seedling is later and concentrated than its regrowths which are the main object to control. The farm practices show that the better way to kill the weed is an integrated control, i. e. the combination of agricultural, biological chemical and other methods as well.