Simple formulae for the kinetic inductance of coupled superconducting microstrip lines in odd mode and even mode have been derived by using the conformal mapping technique. Based on the simple formulae, the geometrical effects of kinetic inductance in odd mode and even mode are analyzed and compared with those of magnetic inductance. The coupling effects of two proximity microstrip lines caused by the kinetic inductance are also studied. The kinetic inductance is dominant for smaller geometrical sizes but is less important than the magnetic inductance for larger geometrical sizes. ©1997 American Institute of Physics.