Confinement properties of a reversed field pinch (RFP), TPE-1Rm20, are intensively presented. Plasma current, Ip, dependencies of confinement properties are particularly shown in comparison with the forerunner machine, TPE-1RM15. The results without any active density controls are presented in this paper. It is shown that the both machines have almost the same, relatively high, I/N values (= 12×10–14 Am) and the poloidal beta, βp, (= 0.1) and they do not change very much with Ip, where N is the column density. The energy confinement time, τE, linearly increases with Ip and the behavior of the resistive part of the loop voltage has an important role to the Ip dependence of τE.