Two novel alkali(l) borogermanates with noncentrosymmetric structures, namely, CsB3GeO7 and K2B2Ge3O10, have been synthesized by high-temperature solid-state reactions in a platinum crucible. The structure of CsB3GeO7 features a novel three-dimensional (3D) framework composed of cyclic B3O75- groups that are interconnected by Ge(IV) cations, whereas the structure of K2B2Ge3O10 is a new 3D network based on cap-shaped [Ge3B2O14](10-) clusters that are interconnected via Ge-O-B bridges. CsB3GeO7 exhibits a second-harmonic generation (SHG) response that is about 1.5 times that of KDP (KH2PO4), whereas the SHG signal of K2B2Ge3O10 is very weak. Both compounds are insulators and transparent in the range of 300-5000 nm. The electronic structure calculations for both compounds also have been performed.