Plant phenology, studing periodic life cycle of plant and animal, always is used to indicate climate change. Various vegetation types show different phenological responses to change change. This study aims to analyze the relationships of changes between phenology phases of dominant species and climate variables over the three major grassland types in the Mongolia Plateau, including meadow grassland, typical grassland, and desert grassland. This analysis used phenological and meteorological data from 24 ecological monitoring station in the grassland of inner Mongolia between 2004 and 2013. The results showed that: (1) precipitation shows the increased trend and air temperature decreases before the start of the growing season (SOS) in the study area. Before the end of the growing season (EOS),air temperature decreased and precipitation increased in meadow and typical grassland,but air temperature increased and precipitation decreased in desert grassland. (2) through 10 years (2004-2013),the SOS of meadow grassland advanced by 2.04 days and EOS delayed by 12.68 days, and which lengthened the growth duration about 14.72 days. The SOS of typical grassland advanced by 4.01 days and EOS delayed by 10.35 days; the total growth duration was lengthened by 14.36 days in 10 years. In desert grassland, SOS and EOS advanced by 1.32 days and delayed by 9.58 days, and the growth duration lengthened by 10.90 days. (3) The dominant factor affecting SOS was temperature, rather than precipitation,in grassland vegetation. The SOS showed a significantly negative correlation with the mean air temperature in meadow grasslands in the previous three months, and it advanced 1.123 days with a 1°C increase in average air temperature in the three months prior. However, in typical and desert grasslands, the SOS significantly negatively correlated with the average air temperature of the two months prior, and it advanced by 1.137 days and 1.743 days, respectively, with a 1℃ increase in average air temperature in the two months prior. (4) The EOS in typical steppe was jointly controlled by both of air temperature and precipitation of previous 1-2 months. In particular, there was a significant relationship between the average summer air temperature and precipitation in the current month. In addition, the EOS was delayed by 0.119 days with increased precipitation in the current month. However, a more complicated mechanism presumably controls the EOS of typical and desert grasslands, and no significant relationships between the EOS and climate factors were found.