Realizing the logic operations with small-scale states is pursued to improve the utilization of quantum resources and to simplify the experimental setup.We propose a scheme to realize a general single-mode Gaussian operation with a two-mode entangled state by utilizing only one nondegenerate optical parametric amplifier and by adjusting four angle parameters.The fidelity of the output mode can be optimized by changing one of the angle parameters.This scheme would be utilized as a basic efficient element in the future large-scale quantum computation.