A novel method that can lead to generation of a train of ultrashort optical pulses from cw light in the anomalous-dispersion regime of single-mode fibers is proposed. It consists of copropagating a cw signal with a train of intense pump pulses in an optical fiber whose minimum-dispersion wavelength is chosen such that it falls between the pump and the signal wavelength .The pump pulses impose nearly linear frequency chirps on the signal through cross-phase modulation and at the same time amplify the signal through stimulated Raman scattering

which induce the cw signal to evolve into a train of ultrashort pulses. Numerical simulations are used to study the generation of ultrashort pulse train in various cases.