Located in Ninghua county of Fujian province, the Hucun structural basin is one of the several areas where there crop out Upper Paleozoic and Lower Triassic strata on older metamorphic rocks in northwestern Fujian. Based on the principles of the balanced cross-section and the methods of structure analysis, this paper discusses'the structure style of this basin and comes to the following conclusions; the Hucun structural basin is neither a fault basin on the so-called Northwest Fujian uplift nor a structure window but a remained structural basin formed during southeast-directed imbricate thrusting which occurred from the late Early Triassic to Middle Jurassic in this area. Besides, on the basis of the above study combined with geological data from the adjacent areas, the authors propose a preliminary tectonic model to explain the South China Mesozoic erogenic belt.