In this paper, variations of monthly and annual mean temperature of Changsha, Hunan, during the period of 1911-83 are examined by means of the weighted-running-average (binonial coeffcients method) and spectral estimates. Following conclusions have been obtained.1.In the spectra of monthly and annual mean temperature, a significant maximum of harmonic component with a period of about 2-3 years was found.2.From the weighted-running-average curve of temperature it is clear that the recent 70 yesrs' interval can be separated into two stages. During the period from 1911 to 1946, general warming was observed, positive departure was dominated, while in the period from 1947 to 1933 trend changed and coldness prevailed.Meanwhile, some results of the analysis related to rice product are discussed. The monthly mean temperature for April, May and September in Changsha may well represent the cold and warm for the seed-time, and the tillering stage of the early(season)rice and the heading-flowering stage of the late rice respectively. If the monthly temperature in April, May and September is low, heavy damage of rice product will happen. It shows that the heavy low temperature in growing season over Hunan province is a kind of common phenomenon in space and time.