To provide a rubber-modified aromatic vinyl polymer resin composition excellent in heat resistance, oil resistance and balance of mechanical strength andmoldability and capable of giving an extrusion foaming product having excellent appearance, a sheet thereof, a foamed sheet and a container.

There are disclosed a rubber-modified aromatic vinyl polymer resin composition comprising (A) 10-90 parts by mass of rubber-modified aromatic vinyl polymer resin containing 5-12 parts by mass of rubber particle having 0.5-4 μm particle diameter and being 180,000-280,000 weight-average molecular weight of continuous phase and 0.2-1.0 branch number per one molecule in 1,000,000 of absolute molecular weight measured by GPC-LALLS method, (B) 10-90 parts by mass of polypropylene resin and (C) 2-10 parts by mass of styrene-diene block copolymer or hydrogenated compound thereof based on 100 parts by mass of sum of components (A) and (B), the sheet, the foamed sheet and the container.