This paper examines the political-economic dynamism of China’s cross-strait competition between the People’s Republic of China (PRC) and the Republic of China on Taiwan (ROC) in the Arab world in the late twentieth century, with particular focus on the Saudi-ROC relationship. For many Arab states, especially for those pro-US monarchical states, “China” had meant ROC up to some points in that century. The substantial Arab-ROC diplomatic relations dates back to 1937, when ROC in the war against Japan formed the Chinese Muslim Salvation Association and dispatched the Muslim delegation to Arab states in order to rally political support among Arab Muslims. Leveraging this “hajj diplomacy”, ROC entered semi-official relationship with Saudi Arabia, which became upgraded to a formal diplomatic tie after WWII. Since then, ROC and Saudi Arabia had maintained 44-year formal relationship until 1990 when it became the last Arab state to switch recognition to PRC. The Saudi-ROC tie was primarily based on the Cold War politics as the two states, in firm alliance with the US, shared common political stance against Communism. However, the ROC government had never been at ease only with this common ideational factor. PRC’s growing influence in the Arab socialist states especially after the Bandung Conference (1955) was alarming, and even in Saudi Arabia, PRC began establishing its foothold with “hajj diplomacy” in its hand now. In order to counter PRC’s infiltration into the kingdom, ROC launched what can be called “techno-diplomacy” in the early 1960s as a part of its global anti-PRC campaign. Leveraging its relatively advanced technological standard, ROC made use of technology transfer to Saudi Arabia for reinforcing the political alliance. This strategy was proven effective particularly after the kingdom entered the period of developmentalism with the inception of its five-year development plan in 1970, and it prolonged the formal tie for another 19 years after most of the Arab states switched recognition to PRC in 1971 with the ostracism of ROC from the UNSC. The Saudi-ROC relationship was not only anomalistic but, in fact, reached its heyday in the 1970s and early 1980s as ROC’s techno-diplomacy, constantly upgraded along its own economic growth, won the heart and mind of the modernisation-oriented Saudi leadership. ROC’s techno-diplomacy, nevertheless, declined in the 1980s when the top political agenda in the kingdom became security, ceding the position of “China” to PRC.