Abstract: Based on the data of the daily air temperature and rainfall of 95 meteorological stations over spring corn region from 1970 to 2005,and the phenological observations of the spring corn of 12 agro-meteorological stations of Shanxi Province,the beginning day and variation of the first soaking rain and daily average temperature of ≥10℃ in spring,and the influence of the extreme minimum temperature in May on the growth of maize seedling were analyzed.The results showed that the first soaking rain in spring fell generally between the last ten days of April and the first ten days of May in all regions of Shanxi Province,which conformed to the corn sowing time.The regional drought and non soaking rain occurred frequently,which was disadvantageous to sowing of the spring corn.The beginning day of temperature ≥10℃ had an advanced trend.The extreme minimum temperature in May appeared to be increasing,but there still existed the risk of the spring frost in some years.

Key words: Corn, Corn, Sowing, Meteorological factor, Characteristics of change