Abstract: Based on the importance of reasonable division of the“Three-Zone”to the security and economic of working face in stagger arrangement roadway layout conditions，we proposed a new division method which considered influencing factors such as working face area and fracture angle based on the key stratum theory．The geometric relationships between upper and low key strata，or between key stratum and working face are studied in the experiment；the movement characteristics of heights of caving zone and fracture zone，and the movement characteristics of overburden along the working face direction in stagger arrangement roadway layout conditions determined．The geometric model is established combining with the spatial relationship between the hanging size of key stratum and working area．The results show that working face area，fracture angle，mechanic properties and thickness of rock etc．are the influencing factors of division of the“Three-Zone”．In addition，the influence factor of working area should be considered with the total number of working faces in division of the“Three-Zone”in stagger arrangement roadway layout conditions．

Key words: stagger position, internal-misaligned roadway layout, Three-Zone, key stratum