The thermodynamic properties of the krypton/graphite interface have been evaluated by the grand canonical ensemble Monte Carlo method. Submonolayer adsorption isotherms have been calculated at temperatures of 77.31, 84.11 and 90.12 K, together with particle distribution functions, surface pressures and isosteric heats of adsorption. The results are compared with experiment and discussed in relation to the existence of surface phase transitions. The Monte Carlo adsorptions were used to check the error in assuming Henry's law adsorption at low pressure.