A series of alumino/galloborates, including (H(3)APEA)(6)[Al-B5O10](9)center dot 12H(2)O (1, APEA = N,N'-bis(3-a minopropyl) ethylene di-amine), (HDE-TA)(2)(H(2)DETA)(2)[A1B(5)O(10)](3) (2, DETA = diethylenetriamine), and (H(2)EDAP)[GaB5O10]center dot H2O (3, EDAP = N-ethyl-diaminopropane), was solvothermally synthesized and characterized in solid-state by powder X-ray diffraction, Fourier transform infrared spectroscopy, UV-vis spectroscopy, and single-crystal X-ray diffraction. All of them feature the [MB5O10](n)(2n)-(M = Al or Ga) frameworks, charge-balanced by the long chain-like amine cations. Three frameworks exhibit interlinkage modes of {MB5O10} layers, resulting in channels varying in size and shape. The flexibility of long chain-like amine cations as well as their significant structure-directing functions in forming these crystalline products is also discussed in detail. Powder second-harmonic generation measurements showed that all three compounds present a nonlinear optical property, and compound 2 exhibits type I phase-matchable optical nonlinearity.