  Gravitational lensing causes a correlation between a population of foreground
large-scale structures and the observed number density of the background
distant galaxies as a consequence of the flux magnification and the lensing
area distortion. This correlation has not been taken into account in
calculations of the theoretical predictions of the cosmic shear statistics but
may cause a systematic error in a cosmic shear measurement. We examine its
impact on the cosmic shear statistics using the semi-analytic approach. We find
that the lensing magnification has no practical influence on the cosmic shear
variance. Exploring possible shapes of redshift distribution of source
galaxies, we find that the relative amplitude of the effect on the convergence
skewness is 3% at most
