PURPOSE: The titled composition, prepared by incorporating a styrene type thermoplastic elastomer having a specific viscosity with crystalline polypropylene, capable of improving the melt behavior of the polypropylene and reducing the amount of melt sags, and suitable for vacuum and air-pressure forming.

CONSTITUTION: A polypropylene type resin composition prepared by incorporating 85W99wt% crystalline polypropylene having 0.1W10g/10min melt flow rate (MFR) with 1W15wt% styrene type thermoplastic elastomer having (10W40)/ (60W90) ratio between the styrene and butadiene (or isoprene) and 500W10,000 cP solution viscosity (measured by using a 25wt% toluene solution at 25°C). preferably, the resultant blend is once kneaded and formed into a pelletlike compound to give the uniform quality. The moldability, etc. may be further improved due to the synergistic effect by adding 3W15wt% low-density polyethylene having 0.1W10 melt index (MI) and/or high-density polyethylene having 0.05W5 MI or 5W70wt% filler thereto.