A new type of soluble PI/SiO
2 nanocomposite was successfully prepared by sol gel process with the addition of small amounts of γ glycidyloxypropyltrimethoxysilane. Furthermore, the effects of coupling agent on the morphology and properties of the PI/SiO
2 nanocomposite were investigated using UV vis, FT IR and SEM. The density and solubility of the PI/SiO
2 nanocomposite were also measured. The results show that the coupling agent has great influence on the morphology of the PI/SiO
2 nanocomposite.The size of SiO 2 inorganic particle becomes much smaller with the addition of coupling agent, which makes the PI/SiO
2 films become transparent. Fortunately, the solubility of the PI/SiO
2 nanocomposite is also improved by the coupling agent. And all these effects become even clearer with the amount of coupling agent. The density of the PI/SiO
2 nanocomposite is also increased by coupling agent.