A tunable L-band ring Er3+-doped Fiber Laser (EDFL) with Mechanically-induced Long-period Fiber Grating (MLPFG) is reported,in which a 980 nm Laser Diode (LD) is used as pump source, and a 5×10-4 highly Er3+ -doped fiber is used as its gain medium. The optical fiber laser with a wavelength-tunable range of 42 nm(1 562.465-1 604.280 nm)is achieved by adjusting MLPFG fabricated period and altering the angle between fiber and grooved pressure plat. The 3 dB line-width and the 20dB line-width of the laser are less than 0. 04 nm and 0.08 nm respectively, while the Side Mode Suppression Ratio (SMSR) is more than 45 dB. Moreover, the power stability of the laser is better than 0.2 dBm for a prolonged observation. Experimental results show that the tunable EDFL has advantages of wide bandwidth, narrow line-width and stable performance.