Abstract:To construct the ecological management system of white back planthopper (WBPH), Sogatella furcifera (Horvth),the population dynamic of WBPH was investigated systematically in organic rice fields. The effects of natural enemies were studied using the life table and interference index of population control (IIPC). The results showed that the WBPH occurred two generations in the paddy fields annually. The two peak periods were from the first to the second decades of May, from the first to the second decades of June, respectively. The average number of WBPH was 435.4 individuals per 100 plants during the first generation, and 216.3 individuals per 100 plants. The increasing rates of WBPH in organic rice fields during the second one were 30.79%, 40.44% higher than those in conventional, respectively. The number of natural enemies increased rapidly after the rice planted. The amount of spider was 2.56 times of that in conventional rice fields after rice planted 15d. After rice planted 42d and 38d, the amount of predators, parasites were 1.64, 1.40 times of those in conventional rice fields, respectively. To add up the effects of the natural enemies’ factor, predators and others, parasites had a significant role in control WBPH, which EIPC value in organic rice fields were higher than that in conventional rice fields.