Abstract:Abstracts:The paper is controlled 2~3 instar larvae of Parocneria orienta by Air Tractor (AT-504 ) in Qiqu Mountain National Forest Park in Zitong County in Sichuan Province, which is complex& steep terrain for the first time,the flow is 2400 mL·hm-2, spray rate is 80 m, the average droplet density is 15 per square centimeter, the droplet diameter is 140 to 200 μm, the coverage of droplet is more than 90%. The results showed that there is no significant difference that the air tractor sprays in the complex mountainous than in the plains, 89.5% and 88.0% of its population can respectively reduce after 15 days when the use of 1.2% nicotine matrine EC and 3% fenoxycarb EC 15 days .So it is significant difference. Not only in the plain areas but also in the complex mountainous, Air tractor can be effective used to spray on agricultural and forestry .It has the advantages of effective, low cost, high efficiency, It can be used in various terrain.