By analyzing the propagating equation of ultrashort optical pulses in a single mode fiber, the bright and dark solitary wave solutions of the equation are obtained. The results show that the ultrashort optical pulses can propagate in a single mode fiber in form of the bright or dark solitary waves without the soliton self-frequency shift. That is significant for the long distance and stable propagation of ultrashort optical pulses and the system of optical soliton with ultra-high speed.