This paper will propose a way to extract target position/range information from the angle-only tracking data with the priori knowledge of the target movement. The target trajectory can be expressed as a function of time, called target function, with n parameters. If m parameters (e.g. target original position, target speed, target acceleration, etc.) are known, or can be estimated to some extent of accuracy, then there remain n-m unknown parameters in the target function. In order to determine these unknown parameters, we should take at least n-m set of tracking data at different times, and construct a system of n-m simultaneous equations. Once all parameters become known by solving this system of equations, the target position and target range can be obtained by substituting the specific time value into the target function. Some typical cases are investigate and the application conditions discussed. Computer simulations are also presented.