All-optical multicasting by exploiting various optical nonlinearities has received considerable attention for performing data routing function from a single node to several destinations directly in the optical domain. Based on the self-phase modulation and followed spectral filtering, simultaneous one-to-six channels all-optical wavelength multicasting for a 40 Gbit/s RZ signal with 100 GHz channel spacing in a dispersion flattened highly nonlinear photonic crystal fiber was achieved. Dynamic characteristic of proposed wavelength multicasting scheme was further exploited. The results show proposed scheme has wide operating wavelength range and high tolerance to signal power fluctuation.