To provide a new transparent resin which has high transparency, is excellent in long-term durability, forms a thick film with a thickness of 400 nm or more, and furthermore has a refractive index of 1.6 or more, to fields of optical materials and electronic materials.

In a method for producing a resin composition, at least a compound (A) represented by formula (1) (in formula, M is zirconium or titanium, R¹ is an organic group, and R² is an alkoxyl group, an acyloxy group, or a halogen group), a silicone resin (B) represented by formula (2) (in formula, R³ represents a hydrogen atom or a methyl group, and an active hydrogen group of a silicon-hydrogen bonding group is contained in a ratio of 40-500 g/equivalent), an inorganic salt (C), and water (D) are mixed with a ratio of 10-200 mol of (B) in terms of the number of moles of the active hydrogen, 0.01-5 mol of (C), and 80-300 mol of (D) with respect to 100 mol of (A) and are made to react with one another.