The thesis seeks to explore the triangle of Sino-Russia-US in the second term of Obama administration with a special focus on the interactions among the three state actors on four specific parameters/issues, trade, counter-terrorism, the South China Sea issue and the THAAD issue. The thesis adopts Realism including offensive realism and theory of triangle, and Liberalism composed of neo-liberal institutionalism and economic interdependency to analyze the new triangle. On each parameter, the thesis conducts discussions on the basis of three bilateral relations—Sino-US relations, Sino-Russia relations and US-Russia relations—to understand the triangle of Sino-Russia-US from the microcosmic view. Through analyses, the thesis concludes that different from the classic “romantic triangle” in the Sino-SU-US period, the type of Sino-Russia-US triangle is dynamic due to China’s rise, Russia’s “tough diplomacy” and more complicated international situations, and denotes that the triangle of Sino-Russia-US are still full of uncertainties in the future against the context of changeable international environment, thus making it a significant topic in the international relations.