Abstract: Polistes (Megapostes) rothneyi grahami van der Vecht is one Species of social wasps which occurs in abundance and is distributed over a large area of China．The wasps has three generations per year．The overwintered adult begins to build new nests and lay eggs in spring．Its first generation appears in June，the second one in July and third one in August．The development of the wasp and pine caterpillar can be found concurrently．The period between mid-August and the beginning of September is the best to control the caterpillar，because there are a lot of third to fifth-instar pine caterpillars．According to observations，It was found that applying the wasp to control first to second-instar or seventh to eighth-instar caterpillars is not effective．Finally their attack patterns have been Studied by releasing differellt numbers of nests of the wasp on Miyun Reservior Tree Farm．