Two new borate compounds, C4H10N2·B6O8（OH）2 and （NH3CH2CH2NH3）B5O8 （OH）2, have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR, elemental analysis and thermal analysis. Compound 1 crystallizes in the monoclinic system, space group P21/c, with a = 8.3318（17）, b = 6.2118（12）, c = 12.479（3） A, β = 108.96（3）°, V = 610.8（2） A^3, Mr = 313.02, Z = 2, 13,.= 1.702 g/cm^,/J = 0.150 mm^-1, F（000） = 320, R = 0.0387 and wR = 0.0924. Its layered structure is linked by infinite covalently coordinated neutral sheets with 3,20-membered window system, which are built up from alternative B6O8（OH）2 subunits donated by two piperzazine nitrogen donors. 2 crystallizes in monoclinic, space group Co, with a = 6.7207（13）, b = 11.481 （2）, c = 12.564（3）A,β = 95.25（3）°, V = 965.4（3） A^3, Mr = 261.18, Z = 4, Dc = 1.797 g/cm^3,/t = 0.164 mm^-1, F（000） = 536, R = 0.0396 and wR = 0.0752. Its oxoborate structure is generated from the sheets of 3,9-membered boron rings bonded diamine molecules through electrostatic and H-bonding interactions to form a two-dimensional layered network.
