A prepolymerized resin and a preparation method thereof are provided, the method comprising a step of pre-reacting bis(vinylphenyl)ethane and polybutadiene. Bis(vinylphenyl)ethane may include 1,2-bis(4-vinylphenyl)ethane, 1,2-(3-vinylphenyl-4-vinylphenyl)ethane, 1,2-bis(3-vinylphenyl) ethane or a combination thereof. Polybutadiene has a 1,2-vinyl content of 85% or above and a number average molecular weight of less than 3000. A resin composition comprising the prepolymerized resin and an article made from the resin composition are also provided.