Atmospheric conditions over Indonesia regions have different characteristics from the atmosphere in other equatorial regions. This is due to its unique geographical location, located between two great continents, Asia and Australia as well as the two great oceans the Pacific and Indian. This research will be carried out observations using radio acoustic sounding system (RASS) that is useful to know the atmospheric conditions in the Kototabang area (west Sumatera), especially virtual temperature parameter/Tv. From the research that has been done virtual temperature value/Tv ranging from 40 ⁰C to - 90 ⁰C  at a height ranging from 1.5 km up to 13 km. The variation of virtual / Tv temperature data from the calculation of standard deviation obtained is quite large close to about 12.