A film-formable emulsion type silicone composition for an air bag, which comprises the respective amounts of colloidal silica-silicone core shell material comprising 80% to 5% by weight of a core comprising colloidal silica (A)(a) and 20% to 95% by weight of a shell comprising a particular polyorganosiloxane containing an ethylenically unsaturated group (b), a particular polyorganohydrogensiloxane (B), a curing catalyst (C), an emulsifying agent (D), and water (E), is disclosed. The composition can form an elastomeric substance having excellent adhesive properties to air bag base cloth, gas tightness, and mechanical strength on an air bag base cloth by removing water therefrom.