Abstract: Climate change often leads to the fluctuation of wheat production, and May is the key period of winter wheat growth, the climate change during this period has significant impact on winter wheat yield. To promote the yield of winter wheat, the correlation between climate data such as temperature, precipitation and sunshine in May of each year from 2000 to 2015 and winter wheat yield in Baoji were analyzed. The results showed that the suitable temperature for winter wheat growing in May in Baoji area was about 20℃; there was a negative correlation between the yield of winter wheat and the precipitation in May, but the increase of winter wheat yield caused by the decrease of precipitation was not unlimited; there was no obvious linear correlation between the yield of winter wheat and the cumulative duration of sunshine in May, but the yield would increase gradually with the duration of light, and sufficient light was significant for winter wheat growth in May.