Screening of the electric field of a test charge by monolayer and double-layer composite fermion systems is considered taking into account the influence of the sample boundary. It is shown that the test charge field is partly screened in the system at distances much larger than the magnetic length. The value of screening as a function of distance depends considerably on the filling factor. The effect of variation of the value of screening in a double-layer system upon a transition to a state described by the Halperin wave function is determined. ©1998 American Institute of Physics.