The construction, principle and main technical performance of the full-face variable diameter slipforms of inclined shafts are concisely introduced. In underground water conveyance system for Three Gorges Project's permanent lock, the inclined shafts are large in number, short in length, complex in structure, changeable in height and so on. Some new techniques of the full-face variable diameter slipforms are taken in concrete construction. The inclined shafts are accomplished with single-pass pouring practice and the change of height is finished automatically with slipping. Its economic and social effect is obvious.