The　band　structure　of　InGaAs　strained　quantum　wells　are　investigated　using　8X8　Luttinger-Kohn　Hamiltonian　including　conduction　band,　heavy　hole,　light　hole,　spin-orbit　splitting　and　strain　effects.　The　energy　dispersion　curves　of　conduction　band　and　valence　band,　the　material　gain　spectra　of　TE　and　TM　mode　are　given,　respectively.　The　variation　of　peak　gain　with　carrier　density,　temperature,　well　width,　and　Indium　composition　of　InGaAs　are　calculated.　The　calculations　show　that　the　higher　the　In　composition　of　InGaAs　and　the　thicker　the　well,　the　longer　the　emitting　wavelength　are.　The　higher　carrier　density　and　higher　In　composition　lead　to　the　higher　peak　gain.