Based on nonlinear Schrdinger equation, the stimulated Raman scattering (SRS) chirp, self-steepening (SS) chirp and total chirps induced by all nonlinear effects in photonic crystal fiber (PCF) are simulated numerically. The results show that the center of SRS chirp wanders and the chirps of the leading edge and the trailing edge are asymmetrical, the central SS chirp mainly shifts to the trailing edge, and the total chirps increases. Thus, SRS leads to the shift of spectrum to the longer wavelength and the asymmetric broadening of spectrum, and SS is the most important contributor to the asymmetry spectrum broadening. Consequently, asymmetrical red-shift supercontinuum (SC) spectrum is finally resulted due to all nonlinear effects mentioned above.