Abstract: In modern times, in order to resist the impact of foreign yarn and cloth, solve the problem of people ’s clothes and quilts, fill the economic gaps, Yunnan spared no effort to promote cotton planting campaign throughout the province. Cotton planting areas in Yunnan are mainly located in dry and hot valleys such as Jinsha River, Nanpan River, Yuanjiang River and Lancang River, showing a narrow distribution along the valley zone. Although the government vigorously promoted cotton planting campaign, but the results are not significant, did not fundamentally solve the problem of cotton shortage in Yunnan. To investigate the reasons for the failure of the cotton planting movement in Yunnan in modern times, besides personnel and war, environmental factors such as light, heat, rainfall, soil, topography, diseases and insect pests should also be discussed.