Using the nonlinear polarization rotation mode-locking and cavity dispersion management,we report the direct generation of 50-fs pulses from a stretched-pulse Er-doped ring laser with all-fiber construction.The average output power was 56.4 mW under a 330 mW pump power with a repetition rate of 37.8 MHz,which had relatively high conversion efficiency of 17% for all-fiber construction.The pulse energy was greatly improved to 1.5 nJ.The smooth output spectrum without any side lobe showed the laser worked on the single-pulse operation.