A band edge model in (101)-biaxial strained Si on relaxed Si1-xGex alloy, or monoclinic Si (m-Si), is presented using the k p perturbation method coupled with deformation potential theory. Results show that the [001], [001], [100], [100] valleys constitute the conduction band (CB) edge, which moves up in electron energy as the Ge fraction (x) increases. Furthermore, the CB splitting energy is in direct proportion to x and all the valence band (VB) edges move up in electron energy as x increases. In addition, the decrease in the indirect bandgap and the increase in the VB edge splitting energy as x increases are found. The quantitative data from the models supply valuable references for the design of the devices.