Knowledge about response of crop phenology to current climate change is of much importance to predict its response to future climate change scenario, since it helps reduce the prediction uncertainty. In this paper, based on phonological observation data of summer maize from agricultural meteorological station records and daily meteorological data during 1981-2009 in the North China Plain(NCP), responses of summer maize phenology to climate change were analyzed using linear regression method and significance analysis. Results showed that:(1) over the past 30 years, minimum and average temperature increased significantly(P<0.05) during summer maize growing season in NCP with a trend of decline negatively correlated with latitude. Sunshine hours declined substantially(P<0.01) and precipitation change was not significant;(2) The dates of main growth period of summer maize in the Beijing-Tianjin-Hebei region and Shandong province delayed significantly(P<0.05), while in the Henan province they advanced significantly(P<0.05);(3) The whole growth days in NCP increased with a rate of 2.72d?10y~(-1)(P<0.01), and those in the Beijing-Tianjin-Hebei region had the highest rate of 3.36d?10y~(-1);(4) The whole growth days were mainly negatively correlated with average temperature during the same period. Regression coefficient varied in -7.16~3.17.The reproductive days were also negatively correlated with average temperature. Regression coefficient varied in -3.56~1.87. The results indicated that while temperature increased by 1oC, the days of whole growth period and reproductively stage of summer maize would shorten by 2.71d and 1.07d, respectively. Summer maize in different regions of NCP had different ways of responding to climate change. Suitable seeding time and variety types should be selected according to local response features.