  New V photoelectric observations of the eclipsing system YY CMi, obtained at
La Silla, Chile, and Merate Observatory, Italy, are presented. New times of
minima and ephemeris based on our observations are also given. The V light
curve was analysed by using the WD code to derive the geometrical and physical
parameters of the system. Since no spectroscopic mass ratio is available, the
q-search method was applied to yield the preliminary range of the mass ratio in
order to search for the final solution. First the unspotted solution was
carried out by using the unperturbed parts of the light curve and applying the
DC program of the WD code. The solution was performed by assuming contact (mode
3) and semi-detached (mode 4) configuration, since no classification of the
system is possible from the shape of the light curve. The solution in mode 4
does not lead to an acceptable model, since the secondary was found to be
slightly overcontact. Therefore the contact solution was finally adopted.
Moreover the light curve peculiarities (Max II fainter than Max I and excess of
light around the phase 0.32) were explained by assuming a cool and a hot spot
on the surface of the secondary (cooler) component. The degree of contact is
very small (f about 3%) and the thermal contactis poor (T1-T2) about 650 K.
These results together with the high photometric mass ratio q about 0.89
indicate that YY CMi is very probably a system at the beginning or the end of
the contact phase.
