In the process of the present invention, a polyamide A1 and an organized clay B are mixed mainly by dispersive mixing, and after added with a polyamide A2, mixed mainly by distributive mixing in a corotating intermeshing twin-screw extruder so designed as to effect the dispersive mixing and the distributive mixing. The organized clay B is completely and finely dispersed and distributed throughout the resultant polyamide composite material. Shaped articles such as films and sheets made of the polyamide composite material exhibit excellent gas barrier properties and transparency with little malodor mainly attributable to the decomposed products of the organizing agent for preparing the organized clay B.