Abstract: 【Objective】 To explore the influence of low temperature stress on the growth and development of cotton at bud stage, so as to provide cold-resistant experience for the field planting of early maturing upland cotton in northern Xinjiang, and provide resource guarantee and theory for the screening of low-temperature resistant germplasm resources and the breeding of low-temperature resistant varieties. 【Methods】 Three stages of experimental materials: low temperature gradient or mild hypothermia T₁ (20℃/15℃, day/night), medium low temperature T₂ (15℃/10℃), severe low temperature T₃ (10℃/5℃) and contrast CK (28℃/20℃) were given to study the effects of different low temperature and low temperature cold-resistance on the growth and development of northern Xinjiang cotton varieties of different years: Xinluzao 61, Xinluzao 36 and Xinluzao 10. 【Results】 After 15 d of bud cotton treated under severe low temperature stress, all physiological indicators of the plant were significantly lower than those of mild and moderate temperature stresses, indicating that the lower the stress temperature, the more obvious the inhibitory effect on the growth of the bud cotton. Under the same low temperature treatment, the longer the low temperature treatment lasted, the more obvious the inhibitory effect on the growth of bud cotton. 【Conclusion】 When the low stress temperature is lower than 15℃, the cold resistance of Xinluzao 36 is better than that of Xinluzao 61 and Xinluzao 10. Xinluzao 36 shows more stable crytemperature resistance may be enhanced by inhibiting plant reproductive growth.