To obtain a syndiotactic polystyrene based resin composition good in surface appearance of moldings, reduced in sink marks and, at the same time, improved in toughness with no addition of or a small amount of a rubber component.

Into 100 pts.wt. styrehic resin component comprising (A) 20-80 wt.% syndiotactic polystyrene; (B) 20-80 wt.% total amount of (B1) a polyamide 6 and (B2) a polyamide having a melting point of not lower than 250°C [(B1)/(B2)=2/8-8/2]; and (C) 0-10 wt.% rubber-like elastomer, 1-10 pts.wt. compatibilizer (D) having compatibility with component (A) and, at the same time a polar group reactive with components (B1) and (B2) is incorporated to obtain a desired styrenic resin composition. This composition may contain further 1-70 pts.wt. inorganic filler.