Pine bast scale(PBS), Matsuccccus matsumurae (Kuwana) (Homoptera: Margarodi-dae) is one of the most serious destructive pests of Pinus massoniana Lamb. The distance of wind dispersal of PBS was observed in May 1981 in Mei Yuan Park in Wuxi, Kiangsu. At the peak period of crawlers (1st. instar nymphs), the aerial dis persal was observed with glass slides (76×26mm) lightly coated on one side with petrolatum or cotton. It was placed in the crevises of branches on the top of the broad leaf trees ca. 4m above ground and in openings downwind from the infested forest (5-500m).The exposed slides were examined under 25 × magnification to identify crawlers per day. During the period of study, wind average speed was l-4m/sec.In this study, 326 crawlers (including 75 dead crawlers) and 60 eggs were caught respectively. Numbers of crawlers captured per slide were decreased rapidly away from the edge of the stand. The aireal dispersal of crawlers was observed on one trap at distanceas far as 500m. The wind dispersal crawlers of PBS may be regarded as the main way of the pest distribution in short distance,