This paper reports the growth and spectral properties of Er3+/Yb3+:LaCa4O(BO3)(3). The Er3+/Yb3+ :LaCa4O(BO3)(3) crystal with diameter 30mm and length 40mm was obtained using the Czochralski method. The absorption and emission spectra of Er3+/Yb3+:LaCa4O(BO3)(3) crystal have been investigated. The strong absorption band with absorption coefficient 13cm(-1) at 900-1050 nm was observed in Er-0.05/Yb-0.5:Ca4La0.45O(BO3)(3) crystal. The emission band in 1510-1580 was observed, and its fluorescence lifetime is about 1.22 ms at 300K. (C) 2002 Elsevier Science B.V. All rights reserved.