Abstract: In order to serve the agricultural production structural adjustment, fully utilize heat resources and prevent frost damage, the author adopted climate data from 1953-2012 and the climate diagnose analysis method, to analyze the variation of heat resources and frost period of Western Liaoning. The results showed that the change rate of annual average temperature, average temperature of summer half year, average temperature of winter half year in Western Liaoning was 0.311℃/10 a, 235℃/10 a, 219℃/10 a, respectively. The annual average lowest temperature, the annual average temperature and the average highest temperature had warming mutations during 1986-1988; after such warming mutations, active accumulated temperature of recent 20 years (1993—2012) of ≥0℃ and ≥10℃ had increased 256℃·d and 233℃·d, and the first date of frost was postponed by 8 days. Even though heat resources had increased, yet the final frost date did not end in advance, therefore, the field sowing time could not be moved ahead. The first frost date was postponed significantly, so the principle of postponing the mutual period could be considered, and the postponing of the sowing date by 8-10 days could reduce 95% of the final frost threats. The high temperature, the increasing accumulated temperature and the extension of non-frost period in Western Liaoning could promote the regional development of agricultural economy.