Based upon the field investigation and the results of rock mechanics tests, the Wenjiashan lotus-shaped structure and its engineering geomechanical conditions of rock mass are discussed in this paper.1. Wenjiashan lotus-shaped structure is a small twirling structure which consists of a group of rotational faults caused by torsional compression forces;2. Within the lotus-shaped structure, different types of rock mass structure show different distribution patterns, which are strictly controlled by both whirl planes and whirl strata. Bach type of rock mass structure has its own mechanical characteristics;3. According to the deformation properties of rock mass in lotus-shaped structure, four zones (or regions) can be distinguished: elastic deformtion zone, quasi-elastic deformation zone, elasto-plastic deformation zone and plastic deformation zone;4. Both the nuclear pillar and the central parts of the whirling strata within lotus-shaped structure are the favourable regions of engineering geomechanical condition i.e. the elastic and quasi-elastic deformed zone; the marginal parts of the whirling strata, i.e. elasto-plastic deformed zone, are the less favourable regions, all of the plastic deformed zone in the whirling planes are unfavourable regions.