To monitor change, protection and utilization of the grassland environment and assess the effect of regional climate change on grass growth, we investigate the relationship between the dominant pasture growing season in typical grassland and the change of climatic factors. Based on phenological observation data during the growth period and meteorological observation data for Stipa krylovii Roshev and Leymus chinensis (Trin.) Tzvel in Central Inner Mongolia from 1983 to 2009, we analyze the relationship between meteorological elements such as temperature, precipitation and typical plant phenological period using statistical methods. The analysis revealed the following. 1) Average temperature had a significant increasing trend in spring, summer, autumn and the entire year, and the spring trend was 0.71-0.84℃/10 a. Precipitation decreased in all seasons except spring. Climate change had warming and drying trends over the last 27 years in the principal grasslands of Central Inner Mongolia. 2) The green-up stage had a trend toward delay and positive correlation with precipitation during April for Stipa krylovii Roshev and Leymus chinensis (Trin.) Tzvel at Xilinhot. However, green-up had a trend toward advance and had negative correlation with temperature and precipitation from March through May for both grass species in Xianghuang Banner and Chahar Right Back Banner. The green-up of dominant pastures advanced 3-5.1 d and 1.3-2.1 d for Stipa krylovii Roshev and Leymus chinensis (Trin.) Tzvel, respectively. 3) The yellow and withered period had a trend toward advance and negative correlation with temperature between August and September, and positive correlation with precipitation. With a 1℃ temperature increase, this period advanced 1.7-10.7 d for Stipa krylovii Roshev, and Leymus chinensis (Trin.) Tzvel advanced 3.5-11.3 d. 4) The growing period for the aforementioned grass species lengthened, and was significantly positively correlated with average temperature from April through October. The growing period for Leymus chinensis (Trin.) Tzvel shortened and was positively correlated with hydrothermal coefficient.