The SCO belongs to a new type of regional organizations of the greatest potential，an important platform of multilateral cooperation on which the regional countries seek stability，development and prosperity. China and Russia are the two member states of the greatest actual strength and influence and Mogolia is the SCO’s first observer state. China，Russia and Mogolia occupies the SCO’s entire northern and eastern parts，whose territory almost accounts for three quarters of the entire territory of all the SCO’s member and observer states. The establisment and institutionalization of cooperative mechanism for China，Russia and Mogolia will surely expand cooperative areas between the three countries in politics，economy and humanities，and promote one another’s development，and the regional stability and prosperity，facilitating the building of an atmosphere of lasting peace，friendship，good neighborhood，prosperity and harmony. This paper focuses on discussion of the current situation，perspective and challegens of the cooperative mechanism of China，Russia and Mogolia constructed on the SCO’s basis，and relevant issues on the construction of the economic corridor of the three countries.