A novel low-temperature co-fired microwave dielectric composite composed by ceramic and glass is invented and manufactured. This composite material comprises 85 to 99 wt% of microwave dielectric ceramic, which is [1-y-z[(1-x)Mg2SiO4-xCa2SiO4]-yCaTiO3-zCaZrO3, wherein 0.2 ≤ x ≤ 0.7, 0.05 ≤ y ≤ 0.3 and 0.02 ≤ z ≤ 0.15], and 1 to 15wt% of high chemical stability with Li2O-BaO-SrO-CaO-B2O3-SiO2 glass respectively. In this invention, in order to reach the low sintering temperature of ceramic for co-firing with Ag or Cu electrode, we used eutectic phase of ceramic oxides to reduce its melting temperature, furthermore, a low melting-point glass material with high chemical stability as a sintering aid is added to oxides. This glass composition is included the raw material powders of Li2O, BaO, SrO, CaO, B2O3 and SiO2, and obtained by mixing all ingredients together and melting in the temperature range between 1000 to 1300 DEG C. After quenching and crashing, this glass composite with proper amount is added to the main ceramic oxides and formed the final composition of this invention. The ceramic/glass composite material can be co-fired with an Ag and Cu electrode at 900 DEG C-970 DEG C for 0.5-4 hours in air and protective atmosphere. After sintering, this dielectric material can possess the excellent microwave dielectric properties, dielectric constant between middle-K to low-k at 8~15, high quality factors, low dielectric loss, low temperature-capacitance coefficient and superior chemical stability. Due to above advantages of such a low-temperature co-fired microwave dielectric composite; it is quite suitable for application on manufacture of multi-layer ceramic device.