  We report the results of a search for variable stars in the open cluster NGC
2141. Ten variable stars are detected, among which nine are new variable stars
and they are classified as three short period W UMa type eclipsing binaries,
two EA type eclipsing binaries, one EB type eclipsing binary, one very short
period RS CVn type eclipsing binary, one d type RR Lyrae variable star, and one
unknown type variable star. The membership and physical properties are
discussed, based on their light curves, positions in the CMDs, spatial
locations and periods. A known EB type eclipsing binary is also identified as a
blue struggler candidate of the cluster. Furthermore, we find that all
eclipsing contact binaries have prominently asymmetric eclipses and O Connell
effect (O Connell 1951) which increases with the decrease of the orbital
periods. This suggests that the O Connell effect is probably related to the
evolution of the orbital period in short period eclipsing binary systems.
