Abstract: Along with the economic progress and the living standard enhancement,the building scope and energy consumption of Lhasa had a large-scale expansion.Through two field investigations in winter,the basic survey items,such as indoor air temperature,the evaluation of the thermal environment and so on were analyzed.The result shows that the direct gain system and the attached solar space system are used spontaneously for the existing residential buildings.However,the indoor thermal environment still needs to be improved.Considered that Lhasa city was classified into heating area,the city faces the problem of huge increasing of the heating energy consumption.The basic model of direct solar gain system was established based on the common residential buildings,and the basic elements of passive design were analyzed by the simulation.The last result gives reasonable suggestion on the local residential building design.