This paper studied the low temperature co-fired ceramic (LTCC) powders based on BaOTiO2- B2O3-SiO2 glass-ceramics that is coated with Al2O3 using co-precipitation process. The Al2O3 coating is made from aluminum isopropoxide precursor solutions. Atomic Absorption spectrometer and TEM methods are employed in this experiment. After calcinations, the alumina coating is strongly adhered to the LTCC particles’ surface. The Al2O3 coating is able to prevent soluble Ba2+ from dissolving in water and the effect grows with the increasing mass fraction of aluminum isopropoxide precursor in the co-precipitation system. The optimum mass fraction of alumina isopropoxide coating precursor is about 6wt%.