The locust affected area in Hebei province has reached beyond 200,000 hectares, the worst in last 10 years. The locust density in some areas is more than 5000 per square meter. The experts analyzed the cause. The locust plague happened in large scale last year, and the autumn locusts were especially dense. Secondly, the drought this year has provided favorite hatching and living conditions for locust to break out. It is getting close to the time that locusts begin to migrate, and thus without effective control locust disasters will happen and destroy the agricultural production in the north.