A field assembled optical connector is provided. The connector includes a ferrule having an optical fiber, a plug integrally forming a housing coupling part, and an open-topped boot into which an optical cable is inserted, an optical connection member to connect an optical fiber of the ferrule inserted at a tip end side and an optical fiber of the optical cable, a boot cover rotatably coupled to the plug on a side of the boot, a screw cap screw-coupled to the boot and the boot cover to fix the optical cable inserted into the boot and the boot cover, and a plurality of ring-shaped bosses arranged at inner sides of the boot and the boot cover.