Two novel rare-earth beryllium borates ReBe2B5O11 (Re = Y, Gd) have been discovered. These materials possess a unique structural feature with a platelike infinite (2)(infinity)[Be2B5O11](3-) superlayer, which is first found in beryllium borates. The superlayer can be seen as sandwich-shaped with (1)(infinity)[B4O8](4-) chains linking up with a (2)(infinity)[Be2BO5](3-) sublayer above and below via the B-O-Be bond. Each (2)(infinity)[Be2B5O11](3-) layer is further connected to the neighboring layer through Re3+ cations coordinating with O atoms. Both of these two crystals have very short cutoff wavelengths below 200 nm and exhibit relatively large nonlinear-optical (NLO) effects, indicating their promising applications as good deep-UV NLO crystals.