挂羊头，卖狗肉

Explanation: Analogy to the name of doing good sign, actually selling inferior goods. 　　Source: "Spring and Autumn Annals miscellaneous articles under the" service of the king to the inner and the ban of on the outside, still hanging on the door and the first cow preserved in horses are also sold. "Song explained Lifeline" Wu Deng Hui Yuan "Volume sixteen hanging a sheep's head and sell dog meat, a bad last in, first few off." 　　Examples: China is now the diehards, it is so. They mouth the constitutional, but "~." (Mao Zedong's "Constitutional Democracy")