The conservative physical quantities,dry energy potential vorticity(DEPV) and wet energy vorticity(WEPV),which combine the energy synoptic meteorology with dynamics of the atmosphere,are derived from the basic atmospheric motion equation and the concept of total atmospheric energy.It is found that the energy potential vorticity(EPV) expressed by the static temperature is easier in mathematical computation with clearer physical meaning.DEPV and WEPV are applied to diagnose a typical thunder wind case in Hubei in 2007.It shows that both DEPV and WEPV could forebode the thunder wind weather.The enhancing and descending of DEPV in the upper troposphere increase unstable energy in the middle and lower troposphere,which promotes the thunder wind.It indicates that the thunder wind will occur in the superposition between the high WEPV region in the lower troposphere and the baroclinic system.