The synthesis of organic-inorganic hybrid precursors for low-melting glass has been proposed. In this process, a non-aqueous acid-base reaction of P-OH+Si-Cl→P-O-Si+HCl↑ was employed using orthophosphoric acid (H₃PO₄) and trimethylchlorosilane (Me₃SiCl) as starting materials. The formation of P-O-SiMe₃ linkage and the disappearance of P-OH group were confirmed by ²⁹Si and ³¹P NMR spectra. The viscosity decrease of the precursors observed at high Si concentrations was caused by the decrease in the number of P-OH, which was correlated to the decrease of the hydrogen bond. By the use of P-O-SiMe₃ linkage, low-melting glasses in the system of Me₃SiO_0.5-Me₂SiO-SnO-P₂O₅ have also been prepared through the non-aqueous acid-base reaction. The hybrid glasses thus obtained exhibited low glass transition temperatures, which changed from 29 to −47°C as the -SiMe₃ content increased. Termination of the oxide framework by the organic functional groups lowered the network dimension, giving rise to the lower glass transition temperature.