A supramolecular compound, β-CO-nicotinic acid, was synthesized and characterized by DSC and 1^H NMR. It structure was determined by X- ray single-crystal diffraction technology. The formular is (C42H70O35) ·(C6O2H5N)· 7.53(H2O)·0.73(CH3OH), It crystallizes in the P21 space group of monoclinic crystal system, a=1.51616(4), b= 1.02642(4), c=2. 09296(3)nm, β=110.209(2)°,V= 3.05659(3) nm^3. The refinement converged at R=0.0576. The system belongs to "shallow inclusion" which is rarely found in the solved structures. The guest sits over the narrow rim of the host. The positions of O(66), O(67) and some oxygen atoms of water are disorder. There are so many hydrogen bonds that they build a dense hydrogen bonding net. The hydrogen-bond interaction is the main force to form the whole system and keep it stable.

Key words: CYCLODEXTRIN, NIACIN, SUPERMOLECULAR STRUCTURE, STRUCTURE CHARACTERISTICS, HYDROGEN BONDS, CRYSTAL STRUCTURE