‘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.