We report the observation of amplified spontaneous emission (ASE) in the visible light range in silica-based single-mode optical fibers doped with Er 3+ (Er3+/Al2O3/GeO2/Sio2). Frequency-upconverted emissions were observed simultaneously in a number of visible wavelengths around 463 nm (463 nm , 475 nm , 485 nm , 494 nm , 501 nm and 510 nm), 525 nm and 540 nm (525 nm, 540 nm, 547 nm, 552 nm and 565 nm),around the second harmonic signal wavelength 656 nm (656 nm, 663 nm, 669 nm and 675 nm) and near-infrared lines (782 nm, 802 nm, 809 nm and 823 nm) when the fibers were pumped by a mode-locked, Q-switched Nd3+"YLF laser operating at 1.313 μm. We have observed an interesting phenomenon that the emission spectrum around 463 nm band likely has a cascade amplification enhancement characteristic when the fiber is reported for the first time. The nonpolarization-preserving Er3+-doped single mode fiber used in our experiment had a 6 μm diameter core and a 0.979 μm cutoff wavelength. The NA is 0.235. The Er3+ dopping level is about 500×10 -6. he fiber lengths used were 4.5 m and 3 m separately. The laser power coupled into the fiber is about several hundred milliwatts. The pump mechanism for around 463 nm is that in the first step resonant two photon absorption process the ions are excited to the 4F9/2 level from the 4I15/2 ground state, and a second resonant two photon transition connects ions', 4I9/2 state to the 2G7/2 excited state, giving rise to amplified spontaneous emissions from 2G9/2~11/2 to 4I13/2.