It was originally split into five volumes, two belonging to the Middle Chinese Ping tone (平聲), one each for the other three Middle Chinese tones, Shang (上聲), Qu (去聲); and Ru (入聲). Each tone was split into rimes, and under each rimes were grouped characters of the same onset, and under each entry, was given a brief explanation of its meaning.

The total number of rimes in Guangyun, split over the four tones is 206.