‘Tianjiao No.12’ is a new mid-early maturity hot pepper F1 hybrid developed by crossing long claw pepper inbred line‘ 138’ as female parent and claw pepper inbred line‘ 67’ as male parent. It is of mid-early maturiey. The first flower sets on the 8-10th node. Its fruit is of long claw shape with wrinkles in surface and base．Its fruit is 29-35 cm in length and 3.0-3.5 cm in width. The fruit flesh is 3.2 mm in thickness. The single fruit weight is 50-70 g．It has strong successive fruit setting ability and can bear fruit concentrately. It tastes medium hot. Its dry mater content is 94.7 g·kg-1 . The VC content is 667.7 mg·kg-1．It is highly resistant to pepper blight. It can yield over 60 t·hm-2．It is suitable for cultivation both in open and protected fields.