BaO-B2O3-SiO2 crystallite glassceramics with high thermal expansion coefficient was made by solidstate method.The effect of equivalent replacement of different BaO content by ZnO on the thermal, mechanic and electric properties of BaO-B2O3-SiO2 Glassceramics was investigated.The properties and mechanism of the glassceramics were characterized by XRD and SEM microanalysis.The results showed that when the content of ZnO was less than 3%,with increasing ZnO content,it accelerated the crystallization and the content of cristobalite transformed by quartz decreased to some extent; it also made the glassceramics more dense and increased the bending strength.With the replacement of 5%,liquid phase sintering was inadequate and the glass phase increased rapidly because of the increase of B2O3; the bending strength of glassceramics decreased and the dielectric loss increased rapidly.