  The first photometric analysis of IR Cas was carried out based on the new
observed BVRI light curves. The symmetric light curves and nearly flat
secondary minimum indicate that very precise photometric results can be
determined. We found that IR Cas is a near contact binary with the primary
component filling its Roche lobe. An analysis of the O-C diagram based on all
available times of light minimum reveals evidence for a periodic change with a
semiamplitude of 0.0153 days and a period of 39.7 years superimposed on a
secular decrease at a rate of dp/dt=-1.28(\pm0.09)\times10^{-7} d yr^{-1}. The
most reasonable explanation for the periodic change is the light time-travel
effect due to a third body. The period decrease may be caused by mass transfer
from the primary component to the secondary. With the decreasing period, IR Cas
would eventually evolve into a contact system.
