Aboveground biomass in different rangeland types or same type in different regions varied with time and space which reveals the dynamic relationship between vegetation biomass and environmental factors from different rangeland types and spatial and temporal scales. The results showed that aboveground biomass in Chinese northern steppe rangeland general declined in last 30 years although consistent increased in the recent 5 years. The decline was great in areas with better water conditions and was not significant in local scale. The interaction of annual temperature and precipitation did not have significant effects on aboveground biomass in time scale. The average annual temperature of temperate rangeland had significant effects on aboveground biomass in spatial scale. The precipitation is the main limiting factor of aboveground biomass in alpine rangeland.