Abstract: Zero dispersion point adjusted by structural parameters of TIR-PCF with six-fold rotation symmetry is studied numerically with a multipole method. It is indicated that the zero dispersion point is hardly influence.d by the number of air holes in cladding with large relative apertures. The wavelength of the zero dispersion point becomes shorter with larger size of air holes and longer with larger distance between air holes. As size and distance are small, zero dispersion point appears in a long wavelength region. As size and distance are large enough, the dispersion curve oscillates near the zero dispersion point and several zero dispersion points appear. With constant number of air holes in cladding, the adjustment for zero dispersion point by the number of absent air hole in center core is large.