Wang Niansun (1744-1832) was a distinguished Qing (1644-1912) scholar with tremendous achievements in the study of the Chinese classics and philology. His work, Yanzi chunqiu zazhi (Miscellaneous Notes on the Yanzi Spring and Autumn Annals), has remained an essential reference for Chinese philologists and historians. While Yanzi chunqiu zazhi is comprehensive and meticulous in its analyses, a number of inaccuracies have also been found. The present essay is intended to be a penetrating study of the successes and failures of Wang's work.