CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
We introduce an approach to expand gauge-invariant Wilson operators on the lattice. This approach is based on the non-Abelian-Stokes theorem and overcomes the disadvantages of the Luscher-Weisz method. It is also suitable for expanding any Wilson operator.