Abstract:This paper describes the research status of constitutional water in nominally anhydrous pyroxene group minerals, especially the FTIR characterization and content of constitutional water of jadeite in different rocks. The jadeite minerals from Myanmar were investigated by using micro-FTIR and electron microprobe analysis (EPMA), and the constitutional water characterization of jadeite minerals from Myanmar was studied microcosmically. According to the results achieved, the constitutional water of jadeite minerals from Myanmar is characterized by spectral peaks in the range of 3 610~3 620 cm-1 and 3 540~3 550 cm-1 on the infrared spectra, the content of constitutional water of jadeite minerals in loose structure jade is higher on the outer side and less in the middle, and the constitutional water content in various parts of jadeite minerals with compact structure is fairly homogeneous. Content difference and change trend of constitutional water are not affected by its chemical composition, and probably result from such factors as fluid involvement in diagenesis, jade forming stage and plate subduction and exhumation process. The results achieved by the authors provide a certain basis for the genetic study of Myanmese jade.