(traditional: 馬依澤, simplified: 马依泽, ca. 910 – 1005) was a Muslim Hui Chinese astronomer and astronomer who worked as the chief official of the astronomical observatory for the Song dynasty.
In the early 10th century, the Chinese emperor of the Song dynasty encouraged the advancement of the study of astronomy and its related disciplines. In 961, the Emperor Taizu (r. 960-976) appointed Ma Yize (910?-1005) as the chief official to take charge of the government observatory.
Ma Yize assisted Wang Chuna in compiling several important astrological works, including the Yingtianli (Calendar of Corresponding Heavens). His job was to provide observation, and computation of the regularities in celestial phenomena, using the Islamic methods. His findings were used by Wang Chuna in the compilation of Yingtianli, which was completed in 963. The calculation, based on a 7-day week system similar to that in the Islamic calendar, was first adopted in this document, which was the most important occurrence in the Chinese history of calendrical methods.