Four "picket fence" porphyrin atropisomers were respectively synthesized from the four corresponding atropisomers of meso-tetra(o-aminophenyl)porphyrin that had been chromatographed on a column eluted with petroleum ether and ethyl acetate. Results show that each atropisomer could be successfully synthesized by controlling the acylation temperature at 0 °C. They were characterized by 1H NMR, HRMS, IR, UV-Vis and Langmuir-Blodgett(LB) film analyses. Although the results of HRMS, IR, UV-Vis analyses indicate there is no remarkable difference among the atropisomers, the results of the 1H NMR and the mean molecular areas obtained by LB film technique imply that the atropisomers are significantly discrepant. The former shows that the chemical shifts of the methyl and amide protons of each atropisomer are distinct, while the later presents that the different atropisomer molecules can occupy the different surface areas at the air/water interface.