説文解字
His monumental "Shuowen Jiezi Zhu" (說文解字注 "Annotated "Shuowen Jiezi""), which he spent 30 years to complete, was published shortly before his death (in 1815). Wang Niansun, in his preface to the work, says that "it has been 1,700 years since a work of the same quality appeared" (), suggesting that it is the greatest Chinese philological work since "Shuowen Jiezi", which was published during the early 2nd century.