The chamber walls of two water-cooled calorimetric combustors of different chamber length were electroplated with nickel of diffenrent thickness to investigate decreasing the temperature of the substrate copper wall and prolonging thrust chambers life. Combustion tests were conducted using liquid oxygen (LOX)/gaseous hydrogen, LOX/gaseous methane, and LOX/RJ-1J propellants. The maximum chamber pressure was 12 Mpa and the maximum heat flux reached 120 MW/m2. For both the LOX/hydrogen and LOX/methane propellants, heat flux values measured at the throat section of the nickel plated chambers were 20-30％ less than those measured for the bare copper chamber walls. This infers that subcritical microcracks observed within the nickel layer functioned to relax the layer′s thermal stress and to cause a higher thermal resistance than expected. On the other hand, the test results of the LOX/RJ1-J propellant showed that the wall material and/or temperature, the presence of hydrogen, and the injection pattern of propellants all affected the characteristics of carbon deposition on the chamber wall. It was also experimentally revealed that at the same mixture ratio the heat flux values in the presence of carbon deposition were lowered by 50％ compared to those in the absence of carbon deposition. Both nickel layers survived approximately 30 firing tests having a total duration of 600 s. The durability and reliability of the nickel plating were verified, there by showing that a thin layer of nickel plating is useful for decreasing the heat load of high pressure thrust chambers.