The generalized Huff curve which contains Huffs model as a special case is introduced in this paper.It is shown that every elliptic curve with three points of order 2 is isomorphic to a generalized Huff curve.Some fast explicit formulae for point addition, doubling and tripling for generalized Huff curves in projective coordinates are presented.The generalized Huff curves is also suitable to pairing-based cryptography.