Analytical model for the mechanical behavior of bolted joint subjected to transverse load has been theoretically formulated. It has been shown that transverse displacement of the bolted joint can be separated into five factors: (a) bolt bending due to transverse force acting on the thread surface, (b) bolt bending due to thread surface reaction moment, (c) inclination of bolt head, (d) thread surface slip, and (e) bearing surface slip. In order to calculate the factors (d) and (e), contact force and slip displacement induced on the contact surfaces are modeled while factors (a) to (c) are formulated according to previous theories. In addition, it has been shown that variation in reaction moment induced on the contact surfaces, which affects (b) to (e), depends on contact state. Then, the relation between the reaction moment and transverse load is formulated. We have applied our analytical model to an MI6 bolted joint and confirmed that the model shows good agreement on the load-displacement relation with FEM result.