Intervalence band absorptions of 1.5 μm light in various InGaAs/InGaAsP quantum well laser structures are investigated theoretically. The intervalence band absorption formalism based on 6×6 Luttinger-Kohn Hamiltonian is developed. The absorption tends to decrease with the barrier height of quantum wells. The tensile strain in the well causes the absorption to reduce, while the compressive strain causes it to increase. Also is found that the absorption decreases with increase in temperature.