PMMA and PET thin films doped with (t-Bu)4VOPc {(t- Bu)4VOPc PMMA and (t-Bu)4VOPc PET} and PMMA thin film doped with (t-bu)1. 4VOPc {(t-Bu)1. 4 VOPc PMMA} were prepared on glass substrate by coating (t-Bu)4VOPc PMMA and (t-Bu)4VOPcPET were treated with dichloroethane vapor in a desiccator at room temperature. On the other hand, (t-Bu)1. 4VOPc PMMA was treated with dichloroethane and chloroform vapor in the desiccator at room temperature. The (t-Bu)1. 4VOPc PMMA and (t-Bu)4VOPc PMMA thin films showed SHG and THG after vapor treatment but (t-Bu)4VOPc PET thin film did not. These suggest that the degree of swelling by dichloroethane vapor are different between PMMA and PET. In other words, the aggregation of (t-Bu4) VOPc occurs more easily in PMMA than in PET. The THG of (t-Bu)1. 4VOPc PMMA thin film is larger than that of a (t-Bu)4VOPc PMMA thin film. This means that the molecular size of (t-Bu)1. 4VOPc is smaller than that of the size of (t-Bu)4VOPc.