Abstract: The cold-warm data in winter in Southwest China from 1644 to 1911 were collected and compiled, and the winter temperature series were reconstructed combined with the cold-warm characteristics of modern winter in the study area. Meanwhile, the reliability of the reconstructed series were verified by analyzing their periodicity and abruptness through comparison. The results showed that in the Qing Dynasty the climate of winter in Southwest China was divided into two cold periods, namely 1778—1809 and 1856—1901, and one warm period, namely 1660—1690. Additionally, the mutation of the winter cold-warm sequence in Southwest China obviously occurred in 1780.