  We present the first CCD observations of an eclipsing binary,
ZTFJ015003.88+534734.1, which is a member in the open star cluster UBC 188. The
observations were taken by the 1.88 m telescope at the Kottamia Astronomical
Observatory (KAO) in SDSS griz bands. The latest version of the Wilson-
Devinney (W-D) code was employed for photometric analysis and light curve
modeling of the eclipsing binary. The results indicate that the binary system
is in an over-contact configuration. The mass of the primary star (M1) is
determined to be 1.293 Msun, and the mass of the secondary star (M2) is
directly derived from the system's estimated mass ratio (q= M2/M1) as 0.340
times the solar mass (Msun). We investigated the color-magnitude diagram and
the membership probability of the open cluster UBC 188 using the Gaia DR3 data.
We determined the membership probability of the eclipsing binary
ZTFJ015003.88+534734.1 using the pyUPMASK algorithm and found that its
membership probability is one.
