Er-doped stoichiometric LiNbO3 single crystal fibers were grown by a micro-pulling down (mu -PD) method along the c-axis. The crystals were grown free of cracks and had a uniform shape. We evaluated the homogeneity of the distribution of Er2O3 concentration by electron probe micro analysis (EPMA). We investigated the photoluminescence (PL) properties of the crystal using the 514nm line of an Ar-ion laser by changing the concentration of Er2O3 in the dopant. Result of optical determination, the strong peak of intensity was observed in the green wavelength range around 550 nm. Also, the intensity of PL increased with an increase of Er2O3 concentration and with the power of the laser as excitation source.