Tianyanlun, or the Theory of Evolution, is an important work to modern Chinese intellectual revolution ,while its target readers who ruled and governed China were not enthusiastic enough to initiate change so that the top-to-bottom social reform was not realized albeit the work’s huge influence. The three-word motto of translation cherished by YAN Fu is also questioned when involving ethical factors. Translators as both translational and ethical subjects driven by certain purpose negotiate between source culture and target culture and collude with both for ideological inclinations, which manipulate translation and its ethical orientation. Yan Fu adjusted himself in the collusive network of translation in ethical senses so as to bring the translation to an intended full play, while the decline of Tianyanlun also disclosed the innate illness of the collusion.