A theoretical study is made of the inductive coupling of two superconducting striplines. The study takes advantage of the kinetic inductance, which is remarkable in superconducting films where the thickness is less than the London penetration depth. In the case of weak coupling where the coupled-mode description is most effective, it has been found that the forward-wave coupling leads to power exchange between two striplines with the efficiency of m= kappa 2/( kappa 2+ Delta 2) at a distance of I= pi /2( kappa 2+ Delta 2)12/. Here kappa 2= beta 1 beta 2M2/4L1L2 is the coupling coefficient and delta =(1/2)(B1-B2) is the phase mismatch parameter, where beta i, Li (i=1,2) and M are propagation constants, self-inductances and the mutual inductance of the two striplines, respectively. Numerical studies are also made for new types of kinetic inductance devices for microwave components, i.e. a directional coupler and microwave switch using the scattering coefficients in the general case.