Abstract: The paper aims to provide reference for disaster prevention and mitigation of agricultural production in Shouguang, based on the climatic data (first, last frost date and frost-free period) from 1961 to 2015 in Shouguang by using modern climate diagnostic analysis method, we analyzed the variation characteristics of first, last frost date and frost-free period, and evaluated the influence of first, last frost date on yield of winterwheat and cotton. The results showed that: (1) first frost date showed a delayed trend, but last frost date was ahead of time, leading to an increase in frost-free period; (2) first frost date was postponed and the climate trend rate was 2.23 d/10 a, a mutation existed in 1991; (3) last frost date was advanced with the tendency rate of -1.35 d/10 a; (4) frost-free period increased with the tendency rate of 3.58 d/10 a and had a mution in 1994; (5) first frost day and frost-free period were positively correlated with the yield of wheat and cotton, and last frost date was negatively correlated with the yield of wheat and cotton, and the delay of first frost day made more contribution to the yield of wheat and cotton than that of the advacing of last frost day.