Single crystals of Erbium (Er) doped La 3 Ga 5 SiO 14 (LGS) have been grown along c-axis by using the Czochralski method. The absorption and fluorescence spectra of LGS: Er 3+ single crystals have been measured and analyzed according to the Judd-Ofelt theory. When applied, the following spectral parameters have been obtained: intensity parameters Ω t , Ω 2 = 2.741674×10-20 cm 2, Ω 4 = 0.66934×10 -20 cm 2 and Ω 6 = 0.592591×10 -20 cm 2 , radiative transition probabilities A J,J" , P J,J" . The radiative lifetime of levels 4 I 13/2 , 4 H 9/2 , 4 S 3/2 are 11.333ms, 0.447ms and 0.704ms, respectively. The fluorescence branching ratios and the integrated emission cross sections are also calculated. The results suggest that LGS: Er crystals have potential applications as a laser material.