With -$OCH_2CO$- as a linker, a non ${eta}$-substituted cationic bisporphyrin (4a) and a ${eta}$-substituted cationic bisporphyrin (4b) were prepared through methylation of the intermediate which was obtained from ${eta}$-amino-5,10,15,20-tetra (4-cyanophenyl) porphyrin or 5-hydroxylphenyl-10,15,20-tris(4-cyanophenyl) reacting with 5-hydroxy-10,15,20-trispyridinylporphyrin. Their structures were confirmed by $^1H$ NMR, IR, UV-vis, MS and elemental analysis. DNA photocleavage ability and the singlet oxygen ability of those cationic bisporphyrins were investigated. DNA photocleavage activity of ${eta}$-substituted cationic bisporphyrin was significantly weaker than that of $H_2TMPyP$, but similar to that of non ${eta}$-substituted cationic bisporphyrin. While 4a and 4b showed substantial photocleavage activities toward DNA, with 68% and 66% observed at 10 ${mu}M$. The assessment of indirectly measured $^1O_2$ production rates against $H_2TMPyP$ were described and the relative singlet oxygen production yields were: free cationic bisporphyrins > $H_2TMPyP$. The results showed the cationic bisporphyrins with ${eta}$-substitution and non ${eta}$-substitution could be developed as potential photodynamic agents.