Legal tender issued by the Central Bank of the Republic of China plays an important role in the history of Chinese currency, especially in the history of modern currency. During a period of fewer than 13 years from November 1935 to August 1948, more than a hundred versions of legal tenders with different denominations and designs were successively issued. They were printed by 16 different Chinese and foreign printing companies. A series of legal tenders issued in 1945 were studied using three-dimensional video microscopy, micro-Raman spectrometry (RS), portable X-ray fluorescence spectrometry (pXRF). The results indicate that organic pigments—C.I. Pigments Red 3,4 and 49:1—were used to print red serial numbers and other red patterns of the legal tender, while prussian blue, lead chromate and carbon black were used to produce most of the blue, green and brown colors. These results provide experimental data for the identification, conservation, restoration and research on paper currency and related civilizations.