Abstract: Based on the characteristic basis function method(CBFM), an efficient numerical approach is presented to analyze the electromagnetic scattering characteristics from conducting targets in conjunction with the adaptive cross approximation(ACA) algorithm. The ACA algorithm is applied to compute compressed forms of low rank block submatrices, this means that such matrix can be expressed as the product of a column dominant matrix and a row dominant matrix, which  accelerate the matrixvector multiplication procedure in the generation of secondary level characteristic basis functions (SCBFs) and construction of reduced matrix. Thus, the computational time and memory consumption are reduced significantly compared with the traditional method of moments(MoM). Numerical results demonstrate that the proposed method has good accuracy and efficiency.