An encapsulant composition for a light-emitting diode is provided. One embodiment of the encapsulant composition comprises: (a) about 100 parts by weight of at least one liquid bi-functional epoxy resin containing about 40˜50 weight % of aromatic ring; (b) about 55˜120 parts by weight of a curing agent comprising at least one bi-functional thiol curing agent containing aromatic ring and at least one aliphatic tetra-functional thiol curing agent, wherein the curing agent contains about 10˜50 weight % of aromatic ring and about 20˜35 weight % of sulfur; and (c) about 0.05˜0.5 parts by weight of a catalyst. The encapsulant composition having a high refractive index can be used for a solid state light emitting device to enhance light extraction efficiency.