One of unusual features of high-T_c superconductors, that we discuss in the present report, is related to inhomogeneous distribution of holes. It results in a stripe-phase which consists of antiferromagnetic domains separated by hole-rich domain walls. We study how the upper critical field is affected by this specific distribution of carriers. We consider a two-dimensional square lattice immersed in a perpendicular uniform magnetic field. In order to simulate the presence of a stripe-phase we carry out the calculations for a system with modulated hopping integral. Namely, the magnitude of the hopping integral is constant along the stripe, whereas it oscillates in the opposite direction.

PACS numbers: 74.20--z, 74.80.--g