In this study, effects of the recess ratio and momentum flux ratio on the spray patterns of gas-centered swirl coaxial (GCSC) injectors have been experimentally investigated through cold flow tests in a high pressure chamber, in which the liquid fuel and gaseous oxidizer are simulated by water and gaseous nitrogen, respectively. By elevating the chamber pressure, the cold flow test conditions are adjusted to match the ratios of momentum flux,density, and velocity between the gas and liquid flows to those of the actual hot-firing conditions. The results showed that the spray patterns change drastically from a wide hollow cone to a narrow solid cone as the gas to liquid momentum flux ratio increases.