Thermosetting resin composition, prepreg, and metal foil clad laminate prepared from same. The thermosetting resin composition comprises (A): a solvent-soluble polyfunctional vinyl aromatic copolymer, the copolymer being a polyfunctional vinyl aromatic copolymer having a structural unit derived from a monomer including a divinyl aromatic compound and an ethyl vinyl aromatic compound, and (B): selected from a polybutadiene resin having a number-average molecular weight of 500 to 10,000; the content of vinyl addition across 1, 2 positions in the molecule of the polybutadiene resin being 50% or more. The prepreg and the copper foil clad laminate prepared from the thermosetting resin composition of the present invention have a good toughness, maintain a high glass-transition temperature and a low water absorption, dielectric property and heat and humidity resistance, and are suitable for use in the field of high-frequency high-speed printed circuit boards and for processing of multilayer printed circuit boards.