In this paper, first of all, I clarify differences between a hitherto unknown version of the Wuwang jing found among old Buddhist manuscripts in Japan and the printed version. There are three differences; 1) the sequence of eight kinds of suffering (duhkha), 2) terminology used, and 3) brevity or details of sentences in the same paragraphs.
Secondly, I examine which versions of the Wuwang-jing were quoted in Buddhist writings in both China and Japan, and found that there were seven occurrences of quotations of the printed version and only one of the manuscript version.
Thirdly, in spite of the above-mentioned differences, a close relationship is presupposed because of the high portion of identical sentences. As far as this is concerned, there are two possibilities. One is to assume that the manuscript version was composed by deleting some sentences from the printed version. Another is quite the opposite, i. e., the printed version was composed by adding some sentences to the manuscript version. Internal textual evidence suggests that the second possibility is more likely. In order to arrive at a definitive conclusion, however, a further and closer examination shall be needed.