Abstract: Marxism believes that the replacement of bourgeois domination is bound to be the rule of the people, that is, the mass management of the state. However, due to the management ability of the masses, it is necessary to have a political force to lead the masses forward and guide them to manage the affairs of the state. This political force is the Communist Party. The function of the Communist Party is to guide the masses in running the country and overcome the obstacles to their running the country. To fulfill its duties, the Communist Party must maintain close ties with the masses and respect their dominant position, that is, adhere to the mass line. So the mass line and the Communist Party to fulfill their own responsibilities and missions have internal relevance. Practice of the mass line of the communist party, to play a party main body function, go deep among the masses, to carry out the investigation and study, meet the demand of the masses, education promoted the crowd, put the pioneering experience to rise to the party’s policies, the implementation of the mass line need the communist party and the masses to the joint efforts of both sides, and the mass line is a process of constantly generated.