  The first photometric analysis of V811 Cep was carried out. The first
complete light curves of V, R and I bands are given. The analysis was carried
out by Wilson-Devinney (W-D) program, and the results show that V811 Cep is a
median-contact binary ($f=33.9(\pm4.9)\%$) with a mass ratio of 0.285. It is a
W-subtype contact binary, that is, the component with less mass is hotter than
the component with more mass, and the light curves are asymmetric (O'Connell
effect), which can be explained by the existence of a hot spot on the component
with less mass. The orbital inclination is $i=88.3^{\circ}$, indicating that it
is a totally eclipsing binary, so the parameters obtained are reliable. Through
the O-C analyzing, it is found that the orbital period decreases at the rate of
$\dot{P}=-3.90(\pm0.06)\times 10^{-7}d \cdot yr^{-1}$, which indicates that the
mass transfer occurs from the more massive component to the less massive one.
