  Impacts of observational systematic errors on the lensing analysis of the
cosmic microwave background (CMB) polarization are investigated by numerical
simulations. We model errors of gain, angle, and pointing in observation of the
CMB polarization and simulate polarization fields modulated by the errors. We
discuss about response of systematics induced B-modes to amplitude and spatial
scale of the imposed errors and show that results of the lensing reconstruction
and delensing analysis behave accordingly to it. It is observed that error
levels expected in the near future lead to no significant degradation in
delensing efficiency.
