Abstract: Based on the daily mean temperature data from Huiyang National Basic Meteorological Station from 1967 to 2016, this paper analyzed the variation characteristics of agricultural heat resources in Huiyang by trend analysis, M-K mutation test and wavelet analysis index. The results showed that: the increase of agricultural heat resources in Huiyang in recent 50 years was obvious, specifically, ≥10℃ accumulated temperature and the increase of annual mean temperature showed significant correlation, they both had an increasing trend, the growth rate were 102.6℃?d /10 a and 0.24℃/10 a, respectively; however, ≥10℃ accumulated temperature duration days were increasing slowly and fluctuated with increasing rate of 1.73 d/10 a; the increasing trend of heat resources showed obvious stage with a mutation phenomenon overall in recent 50 years, and the mutation of the annual mean temperatures and ≥10℃ accumulated temperature occurred in 1990 and 1988, respectively, the significant increase of annual mean temperature began in 1996; in addition, the mutation test result of ≥10℃ accumulated temperature days showed a rise and fall alternation trend, it also indicated that there was another rising after 2017; the primary period of periodic oscillations was 24 to 32 years, and during the oscillation cycle of the 10 to 32 years, the periodic oscillations occured 3 high and low alternations, and the oscillations of ≥10℃ accumulated temperature and days were much more frequently than that of annual mean temperature. In the past 50 years, the average temperature and ≥10℃ accumulated temperature were 22.1℃ and 8028.8℃?d, this conditions met the heat demand of the growth of tropical crops, and the triple-cropping of rice’s planting condition. Therefore, considering the increase situation and continue increasing trend of heat resources in Huiyang, it is necessary to evaluate, develop and utilize heat resources reasonably, and to avoid agricultural meteorological risks in a timely and effective manner.