The direct current (DC) and 1/f noise property at low bias current and low frequency were investigated on the high power InGaAsP/GaAs quantum well (QW) laser diodes. By using DC test, we found that V-I and IdV/dI-I are indicators of current leakage. By using low frequency noise (LFN) test, we found that voltage noise amplitude BV ∝IβV. Theoretical analysis and aging tests indicate that current index βV is correlated with the carrier transport and current leakage mechanisms. The small βV indicates that the lasers are unreliability devices with serious current leakage and non-radiative recombination.