According to the air temperature, using linear trend function and Morlet wavelet analysis method, variations of the annual and seasonal air temperature of Bengbu in 1952-2011 were studied. At the same time the variations of the annual maximum, minimum air temperatures were also explored. The effects of the variation on agriculture were discussed. The results showed that: annual average temperature appeared to be rising; the rate of climate tendency was 0.23 ℃?10a~(-1); the warming trend was more obvious in spring, autumn and winter than in summer; the tendency was not clear in summer; annual average air temperature was relatively low before 1990, and to be a fluctuate change; the warming trend was not clear; however, after 1990, the annual average air temperature was relatively high and the warming trend was clear. Annual average maximum and minimum air temperatures showed an increasing trend; the climate tendency rates were 0.01 ℃?10a~(-1), 0.37 ℃?10a~(-1)， separately； the climate tendency rates of annual average minimum air temperature was higher than that of the maximum temperature indicating that the temperature increased more in nighttime than in daytime, which decreased the diurnal temperature range. The increased temperature in nighttime may increase the respiration of plant, which would have negative effect on agricultural production.