《四庫全書》在修纂謄抄過程中，除以消彌違礙文句的理由，對底本進行不同程度的刪改，造成《四庫全書》各閣本內容的差異外。還有許多異文現象成因被忽略，而有賴於分析說明，才能對謄錄人員的素質良莠，和《四庫全書》的版本價值有更為具體的認識。本文以《古今說海》「說選部」為討論範圍，根據文淵閣、文津閣本改動嘉靖本情形進行研究，說明除違礙字句外，造成《四庫全書》與底本異文的原因，包括正俗字通用未統一、形近訛誤倒衍脫漏、刪改譯名序跋抬頭和校勘改訂底本誤謬。據此，不僅可以作為四庫館臣功過論斷的參考，評價文淵閣和文津閣本優劣的依據，使對《四庫全書》異文現象有較為全面性的瞭解，還能突顯《四庫全書》所收錄叢書在四庫學研究上的價值。

On the account of eliminating taboo words, the original edition of Si Ku Quan Shu was expurgated with varying degrees during the process of compilation and transcription, which resulted in different contents in each version of Si Ku Quan Shu. However, lots of causes that contribute to variant characters still remain neglected. Only through analysis and explanation can the qualities of transcribers and version value of Si Ku Quan Shu be specifically realized. Within the category of ＂Shuo Xuan Bu＂ of Gu Jin Shuo Hai, the present study explores how the versions of Wenyuan Ge and Wenjin Ge modified the version of Jiajin. It is found that in addition to the taboo words, the causes that contribute to variant characters between Si Ku Quan Shu and the original edition include failure in unification between formal and folk words, errors in form-similar characters, omission and reversal, deletion and change of translated names and preface titles, and collation of errors in original edition. In light of this, the findings can be served as the reference to the evaluation of Si Ku officials as well as the basis of judgment on the versions of Wenyuan Ge and Wenjin Ge. The variant characters in Si Ku Quan Shu can thereby be comprehensively understood. In addition, the value of book series collected by Si Ku Quan Shu on research of Si Ku studies can also be manifested.