A Relation between flow structure and local skin friction on the wall surface of the clustered linear aerospike nozzle models was investigated by conducting cold flow experiments using a skin friction sensor which has been developed in this study. The skin friction sensor is capable of measuring the local skin friction value on the wall. Measured skin friction value was compared to some existing prediction model and results found that the local skin friction value becomes drastically different from the one predicted by existing models. In cases of over-expansion condition skin friction was drastically increased by oblique shock wave. In cases of under-expansion condition skin friction was increased which was caused by interference of jet boundary of cell-nozzle flows jetted from adjoined cell-nozzle.