An all-fiber regenerative amplifier at 1053 nm is demonstrated. The input signal pulse energy is 75 pJ in a 3.5-ns pulse at a 1-Hz repetition rate. At a low level of input pump power of 110 mW, the saturated output energy is 120 nJ with fluctuation less than 2% root mean square (RMS) even the fluctuation of the input pulse be about 15% (RMS). And the signal-to-noise ratio (SNR) is 66 dB. Maximum output energy of 780 nJ with a total gain of more than 40 dB is obtained at pump power of 130 mW. Scaling to higher pulse energy is constrained by stimulated Raman scattering.