The purpose of the present invention is to provide a composition for forming a semi-rigid polyurethane foam that has low hardness and a resilient feel, has excellent moldability and curability even when made lightweight (made thin), and is suitable for use as an automobile interior material. The present invention is a composition for forming a semi-rigid polyurethane foam that comprises: a polyol mixture (P) that contains a specific polyol (the composition) (A), a water-containing foaming agent (C), and a catalyst (D); and a polyisocyanate component (B). The content of foaming agent (C) is 1.5-2.5 wt % based on the total weight of (A).