This paper reports the fabrication and lasing characteristics of 1.3‐&mgr;m InGaAsP multiquantum‐well (MQW) buried heterostructure (BH) lasers grown by liquid‐phase epitaxy (LPE) technique. The MQW active region consists of five InGaAsP well layers (&lgr;g=1.3‐&mgr;m,Lz∼200 A˚ and InGaAsP barrier layers (&lgr;g=1.1 &mgr;m,d∼400–600 A˚). These lasers have threshold currents of 15–20 mA at 25 °C, external quantum efficiencies of 50% at 25 °C, andT0values of 130–145 °K in the temperature range of less than 300 °K. The beam divergences perpendicular and parallel to the junction plane were in the narrow range of 10–13°. Furthermore, the polarization‐dependent gain‐current relationship between the TE and TM mode of InGaAsP MQW lasers has been investigated in detail for the first time.