Many experiments have proven the potential of power scaling of Yb-doped fibers when they are used in lasers and amplifiers. Recently, photonic crystal fibers have pushed the output parameters of femtosecond fiber laser to compare to the solid-state laser system. Our recently work on this field is presented in this paper. A mode-locking high energy photonic crystal fiber laser operating in the dispersion compensation free regime generates positively-chirped pulses with an average power 2 W of 51 MHz in a stable and self-starting operation. The energy of the pulse is up to 40 nJ and the pulse duration is 450 fs. A domestic Yb-doped double-cladding large-mode-area fiber was used for amplication experiment. With the milliwatt seed laser pulse inputting, 103 gain was obtained.