In the present paper, yielding and propagation characteristics of the stimulated Raman scattering(SRS) and four wave mixing(FWM) were researched in a non-zero dispersion shifted single-mode optical fiber(NZDSF) and standard single-mode optical fiber(SMF) combination under the same pump light and coupling conditions. At 20 m length of NZDSF, The first order Stokes 544.6 nm of SRS gains and is transported by LP01 mode. At 30 m length, 537.7 nm of FWM emerges but 544.6 nm of SRS decreases whose mode is gradually transformed into the LP11 mode. After 80 m length of NZDSF, because the splice point between NZDSF and SMF is a biconical fused taper and their transmission mode interferes with each other, FWM is suppressed and the mode is converted to LP01 again. The phenomena and mechanisms are conducive to inhibiting of optical nonlinear distortion in a dense wavelength division multiplexing system and to developing optical soliton communication system.