An analytical expression of the steady-state laser output intensity of a bistable semiconductorlaser of output- feedback loss-modulation has been obtained from rateequations. Using a CCTS GaAs/AlGaAs SQW semiconductor laser, we have observed the bistability arising from output feedback loss modulation in the semiconductor laser. Compering the theoretical curves of bistability obtained from the rate-equations with the experimental P8tt6rns of bistable Characteristics, we found that there is a good agreement between the two kinds of bistability curves when the device's parameters (for example, feedback loss-modulation coefficient et al.) are changed.