In this paper, two multi-clad RI- and RII-type optical fiber structures for small dispersion and dispersion slope as well as large bandwidth are considered and novel design strategy for this purpose is presented. The suggested design method uses the Differential Evolution (DE) approach. The authors put absolute value of dispersion factor as fitness function in differential evolution method. This algorithm successfully introduces a special fiber including so small dispersion and dispersion slope in the predefined wavelength duration. Also, the proposed method can set zero dispersion wavelengths with high accuracy compared other traditional methods.