Abstract: The Mesozoic structural pattern and evolution of the Bohai Bay basin is debated until now. Especially the Yanshanian deformation pattern is a key problem. We try to select the middle range of the Huanghua Depression of the Bohai Bay basin to study structures of this area, using a large number of seismic profiles. The Mesozoic evolution in the middle range of the depression can be mainly divided into four periods by using the balanced cross-section technique to reconstruct palaeo-structure in conjunction with tec-tonic setting. The first-generation structures are gentle east-west-plunging folds and the following eastwest-striking thrust formed in the late Indosinian. The second-generation strustures are NNE-plunging folds and the following strike-slip faults formed in the early Yanshanian. In the middle Yanshanian, a series of structures were under the ongoing compression, subsequently the dextral normal-slip faults formed under the extension. At last, some normal faults in this area were under regional intensive extension from the late Yanshanian to the early Himalayan.