NA61/SHINE is a fixed target experiment at the CERN Super Proton Synchrotron. The main
goals of the experiment are to discover the critical point of strongly interacting matter and to
study the properties of the onset of deconfinement. In order to reach these goals, a study of
hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus
interactions as a function of collision energy and size of the colliding nuclei. In this talk, the
newest preliminary results on kaon spectra produced in Ar+Sc collisions at three beam momenta
(30A, 40A and 75A) will be shown. The distributions of transverse mass and rapidity will be
compared with results of NA61/SHINE (p+p, Be+Be) and NA49 (Pb+Pb, C+C, Si+Si), as
well as with available world data.