Single crystal Er∶LuAl3(BO3) (Er∶LuAB) is successfully grown using the top-seeded solution growth method with a K2Mo3O10 flux.The cell parameters of the grown crystal are estimated by an x-ray single crystal diffactometor and x-ray powder diffraction analysis.The result indicates that it still belongs to the space group R32.The obtained unit-cell parameters are a =9.2793(19) (A),c =7.210(3) (A),V =537.65(27) (A)3,and Z =3.The absorption spectrum is measured at room temperature.The spectroscopy properties are investigated based on the Judd-Ofelt (J-O) theory,and the effective J-O parameters were calculated to be Ω2 =8.33 × 10-20,Ω4 =3.83 × 10-20,and Ω6 =3.55 × 10-20.The emission spectra of Er:LuAB crystal at room temperature are also studied and the 4I11/2 → 4I13/2 fluorescence around 3170nm is observed.The emission cross section calculated by the F-L formula is 8.6 × 10-20 cm2.These results suggest that the Er∶LuAB crystal may be a promising ～3 μm laser material.