Abstract: Development of fiber optical parametric amplifier(OPAs) is very fast in recent years.On one hand,this paper analyzes several important efficient techniques for improving the peak gain,expanding the gain bandwidth,reducing the polarization sensitivity of fiber OPAs.On the other hand,some typical applications such as lumped amplifying,transparent wavelength conversion,RZ pulse generation,O-TDM switch,all optical sampling,all-optical erasable storage buffer,3R regeneration are fully summarized.Fiber OPAs would be abroad and significantly used in DWDM and all-optical net(AON).