N-(Dehydroabietyl)maleamic acid was synthesized from dehydroabietylamine and maleic anhydride.Its structure was characterized by IR,1 H-and 13 C-NMR spectra.The stereo structure of the title compound was also unambiguously confirmed by X-ray crystal structure analysis.The white crystal crystallizes in the monoclinic system,space group P2 1 with a=12.075(2),b=10.377(2),c=17.840(4),β=100.31(3) °,V=2199.3(8) 3,R=0.0618 and wR=0.1437.Two crystallographically independent molecules with different conformations co-exist in the unit.In each molecule,the two cyclohexane rings form a trans ring junction with chair and half-chair conformations,respectively.The C=C double bond between two carbonyl groups is in a Z configuration.Intermolecular and intramolecular hydrogen bonds coexist to stabilize the structure.