6 agricultural meteorological observatories and 64 meteorological stations in Heilongjiang Province of China were chosen.With maize phenology data and climate data from 1961 to 2009,the maize climate suitability degrees of these stations were calculated,especially in whole growth and each periods of maize.The result indicated the suitability degrees in each period of maize were different from 1961.Temperature suitability degree had increased with year,but sunshine suitability degree had decreased in sowing to emergence,emergence to flowering and flowering to mature.The precipitation suitability degree had declined except sowing to emergence.In whole growth of maize,the precipitation and sunshine suitability degrees were decreased,and temperature suitability degree improved with year.Integrated climate suitability degrees had dropt.The combination of climate factors was effective.