Abstract: The architecture of a constellation can be described jointly by the position of the satellite relative to the earth and the position of the satellite relative to other satellites in the constellation.Due to effect of the disturbance force,the architecture of the constellation will decay gradually.So it needs to be controlled in order to keep the architecture.The mathematical model for the motion of two satellites in the same circular orbit is deduced.And the precision of the model has been tested through the simulation.The control law based on the linear quadratic(LQ)control theory is presented in order to control the relative position of the two satellites.A kind of relative position control strategy cha- racterized with the adjustable nominal position is developed.The validity of the strategy has been explained through the dissertation and supported by the simulation result.