A production method for a GI (graded index) optical waveguide, the production method comprising: a first step of inserting a needle-like portion at a tip end of an ejection unit into uncured cladding; a second step of moving the needle-like portion in the uncured cladding while ejecting an uncured material from the needle-like portion to form an uncured core surrounded and covered with the uncured cladding; a third step of removing the needle-like portion from the uncured cladding; and a fourth step of curing the uncured cladding and the uncured core, characterized in that the uncured cladding is composed of a composition including 100 parts by mass of a reactive silicone compound (a) composed of a polycondensate of a diarylsilicic acid compound A of Formula and an alkoxy silicon compound B of Formula, or a polycondensate of the diarylsilicic acid compound A, the alkoxy silicon compound B, and another polycondensable compound, and 1 part by mass to 200 parts by mass of a di(meth)acrylate compound (b) of Formula, and the uncured core is composed of a composition including 100 parts by mass of a reactive silicone compound (x) composed of a polycondensate of a diarylsilicic acid compound A of Formula and an alkoxy silicon compound B of Formula, or a polycondensate of the diarylsilicic acid compound A, the alkoxy silicon compound B, and another polycondensable compound, and 1 part by mass to 100 parts by mass of an aromatic vinyl compound (y) of Formula: (wherein Ar 1 and Ar 2 are independently a phenyl group optionally substituted with a C 1-6 alkyl group, a naphthyl group optionally substituted with a C 1-6 alkyl group, or a biphenyl group optionally substituted with a C 1-6 alkyl group), Ar 3 -Si(OR 1) a R 2 3-a (wherein Ar 3 is a phenyl group having at least one group having a polymerizable double bond, a naphthyl group having at least one group having a polymerizable double bond, or a biphenyl group having at least one group having a polymerizable double bond, R 1 is independently methyl group or ethyl group, R 2 is methyl group, ethyl group, or vinylphenyl group, and a is 2 or 3), (wherein R 3 and R 4 are independently a hydrogen atom or methyl group, R 5 is a hydrogen atom, methyl group, or ethyl group, L 1 and L 2 are independently a C 2-6 alkylene group, and m and n are 0 or a positive integer, wherein m+n is 0 to 20), (wherein R 6 is a hydrogen atom or methyl group, L 3 is a single bond, a hydrogen atom, an oxygen atom, a C 1-20 q-valent aliphatic hydrocarbon residue optionally substituted with a phenyl group, or a C 1-20 q-valent aliphatic hydrocarbon residue optionally including an ether bond, Ar 4 is a p+1-valent aromatic hydrocarbon residue, p is independently 1 or 2, and q is an integer of 1 to 3 (wherein q is 1 when L 3 is a hydrogen atom, and q is 2 when L 3 is a single bond or an oxygen atom)). a first step of inserting a needle-like portion at a tip end of an ejection unit into uncured cladding; a second step of moving the needle-like portion in the uncured cladding while ejecting an uncured material from the needle-like portion to form an uncured core surrounded and covered with the uncured cladding; a third step of removing the needle-like portion from the uncured cladding; and a fourth step of curing the uncured cladding and the uncured core, characterized in that the uncured cladding is composed of a composition including 100 parts by mass of a reactive silicone compound (a) composed of a polycondensate of a diarylsilicic acid compound A of Formula and an alkoxy silicon compound B of Formula, or a polycondensate of the diarylsilicic acid compound A, the alkoxy silicon compound B, and another polycondensable compound, and 1 part by mass to 200 parts by mass of a di(meth)acrylate compound (b) of Formula, and the uncured core is composed of a composition including 100 parts by mass of a reactive silicone compound (x) composed of a polycondensate of a diarylsilicic acid compound A of Formula and an alkoxy silicon compound B of Formula, or a polycondensate of the diarylsilicic acid compound A, the alkoxy silicon compound B, and another polycondensable compound, and 1 part by mass to 100 parts by mass of an aromatic vinyl compound (y) of Formula: