The band structures of Ga1-xInxNyAs1-y/GaAs compressive-strained quantum wells (QWs) are investigated using 6×6 /k.p Hamiltonian including the heavy hole, light hole and spin-orbit splitting bands. By varying the well width and N composition, the effects of quantum confinement and compressive strain are examined. The valence subband energy dispersion curves, TE and TM optical gain spectra of three possible QW structures emitting at 1.3mum wavelength are given. Our calculations show that the Ga0.7In0.3N0.016As0.984/GaAs QW with well width of 43Å emitting at 1.3mum has maximum optical gain 3270cm-1 and differential gain up to about 0.88×10-15cm2 at the carrier density N=6×1018cm-3. It is suitable for high-speed laser emitting at 1.3mum wavelength.