Substitution reactions of 5-(4-nitrophenyl)-10,15,20-triphenylporphyrin (NO_2TPP) and its metal complexes with different nucleophilic reagents were studied for preparing asymmetric porphyrin. The reaction products are different with the nucleophilic reagents changing, and three different products were found. The first obtaining product was diporphyrin when NO_2TPP reacted with sodium phenoxide or diphenoxide in DMF solution; The second was reduced product 5-(4-aminophenyl)-10,15,20-triphenylporphrin-M(Ⅱ) when the metal (Ni, Zn) complex of NO_2TPP reacted with above nucleophilic reagents, as well as NO_2 TPP reacted with lithium mercaptoethanolate or lithium thiophenolate; The third product CNTPP was achieved with the substitution of nitro group by cyanic anion when NO_2TPP reacted with sodium cyanide. Above results were explained with reduction and single electron transfer reaction respectively. Substitution reactions of 5- (4-nitrophenyl) -10,15,20-triphenylporphyrin (NO 2 TPP) and its metal complexes with different nucleophilic reagents were studied for preparing asymmetric porphyrin. The reaction products are different with the nucleophilic reagents changing, and three different The first was product was diporphyrin when NO_2TPP reacted with sodium phenoxide or diphenoxide in DMF solution; The second was reduced product 5- (4-aminophenyl) -10,15,20-triphenylporphrin-M (Ⅱ) when the metal (Ni, Zn) complex of NO 2 TPP reacted with above nucleophilic reagents, as well as NO 2 TPP reacted with lithium mercaptoethanolate or lithium thiophenolate; The third product CNTPP was achieved with the substitution of nitro group by cyanic anion when NO 2 TPP reacted with sodium cyanide. Above results were explained with reduction and single electron transfer reaction respectively.