  We present a review of the results of long-term photometric monitoring of
selected magnetic cataclysmic binary systems, which belong to a class named
"Intermediate polars". We found a spin period variability in the V2306 Cygni
system. We confirm the strong negative superhump variations in the intermediate
polar RX J2133.7+5107 and improved a characteristic time of white dwarf spin-up
in this system. We have investigated the periodic modulation of the spin phases
with the orbital phase in MU Camelopardalis. We can propose simple explanation
as the influence of orbital sidebands in the periodic signal produced by
intermediate polar.
