The present study proposes an improved method for generating better typical meteorological years( TMYs) used in building energy simulation in China. Modifications are made to the commonly used Sandia method,by optimizing the weightings of indices and thus giving more emphasis to dry bulb temperature and relative humidity and less to wind velocity. After analyzing the solar heat gain on the vertical envelop,an index of diffuse radiation rather than direct normal radiation is added for solar radiation. Using the improved method proposed,TMYs for 5 representative cities of 5 major climate zones in China are generated from the meteorological data recorded during the period 1981—2010. The results show that,compared with previous studies,the monthly diffuse solar radiation of typical meteorological months generated by the improved method are the“closest”to the 30-year average,and the comparison between annual diffuse radiation for the TMY and the 30-year annual average is improved,while little adverse effect is produced on global horizontal radiation comparisons,indicating that the improved method is more suitable to generate the TMY data than previous studies. The present study proposes an improved method for generating better typical meteorological years (TMYs) used in building energy simulation in China. Modifications are made to the commonly used Sandia method, by optimizing the weightings of indices and thus giving more emphasis to dry bulb temperature and After analyzing the solar heat gain on the vertical envelop, an index of diffuse radiation rather than direct normal radiation was added for solar radiation. Using the improved method proposed, TMYs for 5 representative cities of 5 major climate zones in China are generated from the meteorological data recorded during the period 1981-2010. The results show that, compared with previous studies, the monthly diffuse solar radiation of typical meteorological months generated by the improved method are the “closest ” to the 30-year average, and the comparison between annual diffuse radiation for the TMY and the 30-year annual average is improved, while little adverse effect is produced on global horizontal radiation comparisons, indicating that the improved method is more suitable to generate the TMY data than previous studies.