This invention relates to antibody-drug conjugates represented by Formula (I) Ab- (L-D)p, Ab is an antibody； p is 1-8； L-D is a chemical moiety represented by the following formula -Str-(Pep)-Sp-D； Str is a stretcher unit covalently attached to Ab； Pep is a linker； D is anti-tumor agent represented by the following formula wherein R<；20>；and R<；30>；are each independently Ct-C6alkyl, and R<；10>；is a non-hydrogen substituent； or R<；30>；is C1-C6alkyl, and R<；10>；and R<；20>；together with the N form a substituted C3-C7heterocycloalkyl ring； or R<；3>；° is absent, and R<；10>；and R<；20>；together with the N form a substituted heteroaryl ring； Sp-D is a spacer moiety of fomula: This invention also relates to a method of treating cancer, use of antibody-drug conjugates of Formula (I) in therapy, and use of antibody-drug conjugates of Formula (I) in manufacturing a medicament for treating cancer. This invention also relates to method of preparing antibody-drug conjugates of Formula (I).
