Abstract: The data from satellite observation on lightning activities, daily NCEP surface precipitation rate, noon cloud work function and heat fluxes from April 1995 to Dec 2000 were employed to study the seasonal variations of lightning activities and related meteorological factors over the central Qinghai-Xizang Plateau, and the relationship between them. The results indicated that the maximum flash density is in July, and there are more lightning in spring than one may expect. Among the several related factors, only surface total heat flux can be account for the seasonal variation of lightning activities including the spring lightning. In addition, surface precipitation rate (or cloud work function) can better be account for the seasonal variation of lightning activities including the spring lightning when they are multiplied by the Bowen ratio (ratio of sensible to latent heat flux). This suggests that sensible heat flux or the Bowen ratio play an important role in transforming CAPE to updraft kinetic energy, and the later could be regarded as an important parameter of modifying the efficiency of generating lightning for any given value of precipitation rate (or cloud work function).