Sintering is one of the key processes in preparing low temperature co-fired ceramic (LTCC) substrate, which plays an important role on the properties of LTCC substrate. In this paper, the effects of different sintering heating rates on the dielectric properties, warpage, film adhesion and flexural strength of LTCC substrate were studied, and the reasons for the changes of substrate properties were analyzed. The results show that when the heating rate is 8 ℃/min, the dielectric constant of the substrate is 5.788 and the dielectric loss is 8.21×10-4. The substrate basically has no warpage, high density, strong adhesion, and the flexural strength of the substrate is up to 175 MPa。