Powder co-injection moulding (PCM) was carried out by using two feedstocks, 316L(60%) and 316L(40%), as core and skin feedstocks, respectively. The effects of processing parameters such as the pre-filling volume of skin feed-stock, the injection temperature of core feedstock and the injection rate of skin feedstock on the profiles of the two feedstock layers were studied. It was found that the interface between core and skin feedstocks exhibited an arched shape in the transverse plane and a V shape in the longitudinal plane. There is a "maximum thickness" of core feedstock in the longitudinal direction. The penetration length and maximum thickness depended on the injection parameters. The formation mechanism of the interface was studied on the basis of rheological theory. This research provided an experimental base for the simulation work of PCM processes. (C) 2016 Elsevier B.V. All rights reserved.