Abstract: 【Objective】 In order to clarify the cause of the weak and dry death of a large area of Hippophae rhamnoides trees in Aheqi County of Xinjiang and Urumqi County, the investigation of Hippophae rhamnoides forests in two places was carried out in the hope of providing theoretical basis for the effective control of sea-buckthorn pests and diseases. 【Methods】 The standard survey method was used to investigate the situation of Hippophae rhamnoides forest and identify the species of diseases and insect pests.The damaged Hippophae rhamnoides was dissected to determine its harm characteristics and its spawning position was investigated by means of foot survey. 【Results】 Hippophae rhamnoides forest in Aheqi County was harmed by the Cossus cossus (Linne) and the Holcocerus Arenicola (Staudinger), and the Hippophae rhamnoides forest in Urumqi County was harmed by the Cossus cossus (Linne), which caused a large area of Hippophae rhamnoides tree weakness, dry death.In Aheqi County and Urumchi County, the occurrence rate of Cossus cossus (Linne) was 52.25%.In Aheqi County, the occurrence rate of Cossus cossus (Linne) was 62.40%, and the population density was 24.62 per plant, with the highest number of 85 per plant.In Urumqi county, the infestation rate of aromatic Cossus cossus (Linne) was 42.10%, the infestation density was 100.62 per infestation, and the single infestation was up to 288.The number of egg blocks in the position of 91~150 cm of Hippophae rhamnoides trunk was the largest, accounting for 54.10% of the total number of egg blocks.The larva of the current year distributed most in the position of 31~60 cm of Hippophae rhamnoides trunk, accounting for 31.05% of the total number of larvae.When the height of the trunk was more than 180 cm, the number of egg blocks and larvae in the current year decreased sharply or even did not distribute.The number of out-of-year larvae in the root of Hippophae rhamnoides was the highest (423, accounting for 45.58% of the total number), and their number decreased with the increase of trunk height within 120 cm. 【Conclusion】 The dry death of Hippophae rhamnoides in Aheqi County and Urumqi County of Xinjiang was caused by the harm of Cossus cossus (Linne) and Holcocerus Arenicola (Staudinger), and Cossus cossus (Linne) has been serious.The best time for chemical control is the incubation period of the eggs and the period when the newly hatched larvae first drill into the bark, which can be sprayed at the position of 31~150 cm in the cadre of Hippophae rhamnoides.