The present invention relates to a thermosetting resin composition for a semiconductor package and a prepreg using the same. Specifically, a thermosetting resin composition for a semiconductor package which exhibits a low curing shrinkage ratio and has a high glass transition temperature and greatly improved flowability by introducing acrylic rubber and mixing two specific inorganic fillers surface-treated with a binder of a specific composition at a certain ratio, and a prepreg using the same, are provided.