Abstract: Frank E. Marble, a renowned American specialist in aerodynamics and combustion and a member of both the National Academy of Sciences and the National Academy of Engineering, was a close friend and colleague of Qian Xuesen at the California Institute of Technology. This paper comprehensively traces their five-decade-long friendship through its distinct phases: from academic collaboration at the Jet Propulsion Center, to Marble's steadfast support during Qian's political persecution, and finally to his four visits to China that sustained their trans-Pacific connection. The study reveals that the essence of their friendship, rooted in shared scientific ideals and profound human warmth, allowed it to transcend national and ideological boundaries, thereby highlighting its significant academic and humanistic value.