Abstract: The chief measure for energy efficiency of a building is the heat preservation within the building,however,that external thermal insulation on system of organic material has some shortcomings at present,such as bad fireproofing,short lifetime and environmental pollution.Expanded and vitrified microball has some good performances because it is a inorganic material,and adapts to fature energy development trend.It is analyzed to foundation for designing energy efficiency in building to research the performances and application of heat preservation system of expanded and vitrified microball.