The increase of atmospheric CO2 concentration due to anthropogenic activities and hence induced climate change has captured the attention and concern of human society. In this regard, the high resolution forward transport model simulations of CO2 at hourly to synoptic timescales have attracted considerable interest in recent time. This becomes important for predicting the future climate to a high degree of certainty. Extensive studies using high resolution CO2 forward transport models are carried out over the United State, Europe and East Asia. However, such studies are very few over South Asia. In view of this, a high resolution regional forward transport model, Weather Research Forecast model for CO2 (WRF-CO2) is being setup for South Asia to better understand the spatial and temporal CO2 variations over this region. Here, a fully coupled, online, regional air quality model WRF-CO2 has been setup and used for the first time to simulate long term CO2 over South Asian region. Comparison of the model results with the ground–based measurements indicates that the model reproduces the spatial and temporal variation of CO2 concentration with higher bias during the growing season. Model results from WRF-CO2 are able to resolve fine scale structures and are facilitating interpretation of CO2 observations. The WRF-CO2 model was able to reproduce the diurnal pattern of CO2 concentration for two observation stations but amplitude of diurnal cycle of CO2 is not captured by the model, particularly over growing season.