Abstract: Ming Shizong once wrote Guidance to Sacrifice which was printed over one night and sent it to various governmental departments. However, though this Guidance to Sacrifice was known to all people and collected by government, it failed to be recorded in EventRecords of Ming Dynasty. Consequently, many scholars believe that it has lost. Fortunately, the author of this paper found it in An Essay Collection Left by Loyal ZHANG. The discovery of the full text not only shows the reason why historians kept it a secret- harm to Shizong’s image, but clarifies that it was written on March29 instead of on March30.