In this paper, we will review the work on Sb-based midi-infrared laser diodes. The structures investigated in this work are InAsSbP based double heterojunction (DH) and multiquantum well (MQW) structures grown by LP-MOCVD. The parameters of the structures are optimized trough theoretical calculation and device testing. The high performance of the laser diodes emitting in the 3 to 5 um has been achieved.