A method for preparing indenoisoquinoline derivatives represented by the following formula (I) is disclosed, which comprises the following steps: (A) providing a first reactant represented by the following formula (II) and a second reactant represented by the following formula (III): and (B) reacting the first reactant represented by the formula (II) and the second reactant represented by the formula (III) in a solvent and selectively adding R2NH2 therein, to obtain the indenoisoquinoline derivatives represented by the formula (I), wherein, R1, R2, R3, A, X, Y, Z, m and n are defined in the specification.