Opening up new realm of Marxism's sinicization and modernization is an important theoretical subject for the development of the Communist Party of China (CPC) and the national cause, is also a strategic task to push forward the sinicization and modernization of Marxism on the basis of practice. In terms of theoretical implications, the introduction and wide spread of Marxism-Leninism in China pointed out the way forward for the Chinese people and provided them with a new choice, led to and guided the birth of the CPC, which laid an important foundation for opening up new realm. Upholding the leadership of the CPC gives a strong, stable and reliable force for adapting Marxism to Chinese conditions and keeping it in the right direction of development, thus providing a fundamental guarantee for opening up new realm. The new leap marks the development nodes and remarkable achievements of Marxism's sinicization and modernization, which is closely related to opening up new realm. The shift from "one combination" to "two combinations" makes Marxism more closely related to Chinese reality and more Chinese with Chinese characteristics, point out the development trend of opening up new realm. In terms of progress in achievement, During its strive for more than a century,CPC has taken the Sinicization of Marxism as its ideological guidance, institutional guarantee, cultural foundation and spiritual support. Focusing on innovation and publicity, of the theoretical achievements of adapting Marxism to China and The Times, Formed Mao Zedong Thought, Deng Xiaoping Theory, Three Represents Important Thought, Scientific Outlook on Development, Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era, make the ideological essence and spiritual essence of Marxism acceptable to the broad masses of the people. At the same time, with the great rejuvenation of the Chinese nation as its central task, CPC has combined the basic tenets of Marxism with the realities of China's revolution, construction, and reform, united and led the Chinese people in making great achievements in the new-democratic revolution, in socialist revolution and construction, in reform and opening up and in socialist modernization, and in socialism with Chinese characteristics for a new era. In terms of practical requirements, The new journey requires us to focus on new missions and tasks in the new stage of development and deepen our understanding of the theoretical quality of Marxism's sinicization and modernization,which is inherite in one continuous line and keep pace with the times. Grasp the "Six Must Adhere to" put forward by Report of the Twentieth Congress.We should take "people supremacy" as our fundamental starting point, "maintain confidence and self-reliance" as our basic foothold, "integrity and innovation" as our main driving force, "problem orientation" as our realistic focus, "systematic concept" as our key coordination point, and "maintain a global vision" as an important position. As long as we do so, we can push forward the sinicization and modernization of Marxism in the new era,and open up new realm of Marxism's sinicization and modernization.