In 2013, the situation and causes of moldy grain of maize were studied using the production survey and statistical analysis method in order to reduce the grain losses in Heilongjiang province. The results showed that: moldy grain of maize occurred widely in Heilongjiang province, the causes included meteorological factors, such as larger precipitation and higher temperature after harvest in autumn, as well as the speed of growing of planting area, the lag of harvest machinery development and the inadequate storage conditions. And the authors suggest some comprehensive techniques to prevent the occurrence of a large scale of moldy grain. First, it needs to accelerate the breeding and popularizing of new varieties which is precocious, adapt to mechanical harvesting and quickly post-dehydration; second, to accelerate constructing the social service system for the development of harvesting machinery andwet corndrying; and thirdly, to improve the construction of storage facilities. Meanwhile the authors put forward in- depth study, such as analysis of the impact of climate change on maize production in cold area and redistricting the region of accumulated temperature for maize planting, and improve relevant technology system under the local condition.