Abstract: The composite masonry of thermal-insulating lightweight concrete hollow block is a new type of structure with composite polystyrene ( EPS) soil as its inner core and the lightweight ceramsite concrete block as its external mould，because it makes the heat preservation and anti-seismic and integrity as a whole，suitable for buildings in village and town． Considering the different strength of filling materials and different strength of masonry mortar， compressive strength of 9 group specimens of composite block masonry was tested，analyzed the effects of different inner core strength and different mortar strength on the compressive strength of composite block masonry． The test results show that the inner core strength has the largest contribution to the compressive strength of composite masonry， whose influence is significant; mortar strength has weak effect on compressive strength of composite masonry; the compressive strength of hollow block masonry is markedly lower than that of composite block masonry．