A method, system and computer program product for inverting boundary conditions for rock mass field in-situ stress computation for a geologic structure are disclosed. According to an embodiment, the current invention includes a method for inverting boundary conditions for rock mass field in-situ stress computation for a geologic structure, the method comprising: considering physical constraint of the geological structure; deriving and solving normal equations of penalized weighted least squares, said normal equations of penalized weighted least squares partially representing said physical constraint of the geological structure; and outputting boundary conditions and reproducing the rock mass field in-situ stress based on the result of said solved normal equations of penalized weighted least squares.