【Background】 Pontania bridgmannii Cameron infests willow and causes premature leaf yellowing and dropping, insect galls and leaf distortion. It severely affects the growth and landscape effect of willow trees. 【Method】 The damage and the spatial distribution of P. bridgmannii were studied at different locations in Urumqi, and the morphology of P. bridgmannii was observed by using stereomicroscope. 【Result】 Salix babylonica L. and S. matsudana Koidz. L. matsudana f. tortuosa (Vilm.) Rehd. were the most sensitive, the observed damage reaching almost 100%， followed by S. matsudana Koidz., (52.6% of trees damaged), whereas S. alba L. and S. matsudana Koidz. L. matsudana f. umbraculifera Rehd. did not suffer any harm. There were no significant differences by tree orientations and the top, middle as well as lower parts on the crowns of S. babylonica were equally sensitive. Normally, there were 1~3 galls on each blade, with 1 larva per gall. The spatial distribution pattern of larvae was aggregated on twigs. According to the damage rate on S. babylonica in different locations, damage was highest at Xinjiang Agricultural University (8.65%), followed by trees at Honghu in Xinjiang University (5.19%). Trees in the Children′s Park, Western Park, Botanical Garden, Water Park, Hongshan Park, and Shuimogou Park suffered gradually less damage. 【Conclusion and significance】 It provided scientific basis for the prevention and control of the pest.