Low temperature co fired Li2O SiO2 glass ceramics were prepared by sintering method. The effects of K2O content on the thermal properties, crystallization behavior, sintering character, morphology and electrical performance were investigated using thermal expansion coefficient (CTE), differential thermal analysis (DTA), X ray diffraction (XRD) analysis, hot stage microscopy (HSM), scanning electron microscopy (SEM) and volume resistivity. The results showed that the replacement of Li2O by K2O glasses led to the reduce of the glass transition temperature (Tg) and the crystallization tendency, the increases in the coefficient of thermal expansion (CTE) and the crystallization energy (E). Furthermore, K2O is beneficial to the sintering property of the glass powders, and the control of the composition and content of crystal phase. The results of electrical performance showed that K2O improved the electrical property of the glass ceramics significantly.