Abstract: The CENTURY model was used to simulate the dynamic changes in aboveground net primary productivity (ANPP) in the Haibei alpine meadow steppe, based on meteorological data from 1957 to 2014 and measured data from 1998 to 2014. The CENTURY model was coupled with five general circulation models (GCMs) to simulate the impacts of changes in climate and CO₂ concentration on the ANPP in three future periods in the RCP (the latest Representative Concentration Pathways) 4.5 and 8.5 scenarios. The results showed that: 1) The trends in the measured values and the simulated values of ANPP at the research site from 1998 to 2014 were highly consistent (Pearson’s correlation coefficient, 0.67; root mean square error, 19.62 g·m^-2), indicating that the CENTURY model is applicable to the alpine meadow steppe in Haibei. 2) Over the past 50 years, the annual mean minimum temperature, annual mean maximum temperature, and annual mean temperature have significantly increased (P<0.01) in the alpine meadow steppe, and there have been marked fluctuations in annual mean precipitation, with precipitation mainly concentrated in the vegetation growing season. The average value of ANPP in the alpine meadow steppe is 271 g·m^-2. The average ANPP has shown an overall increasing trend, but the trend was not significant (P>0.05). 3) There is a positive rate of change in the ensemble average of annual mean minimum temperature, annual mean maximum temperature, annual mean temperature, and annual mean precipitation during the three future periods: the 2030s (2016-2040), the 2050s (2041-2070), and the 2080s (2071-2099) at RCP4.5 and RCP8.5, relative to the baseline period (2001-2014). If CO₂ fertilization effects are excluded, the ensemble average ANPP of the alpine meadow steppe is predicted to increase by 2.21%, 11.53%, and 17.78% at RCP4.5, and by 8.34%, 21.68%, and 40.32% at RCP8.5, during the three future periods (2030s, 2050s, and 2080s, respectively), compared with the baseline period (2001-2014). If CO₂ fertilization effects are included, the ensemble average ANPP of alpine meadow-steppe is predicted to increase by 2.89%, 14.29%, and 24.28% at RCP4.5, and by 11.57%, 31.74%, and 57.29% at RCP8.5 during the three future periods (2030s, 2050s, and 2080s, respectively). The simulated ANPP results from five GCMs showed good consistency, and the uncertainty caused by combining climate models with the CENTURY model was in a reasonable range.