[en] Full Text: The XII Department of the Institute of Nuclear Physics was involved in the following experiments and projects in the year 2001: * ZEUS experiment at HERA (DESY), which focused the main activity of the Department. The group from our Department participating in this experiment consisted of physicists: J. Chwastowski, A. Eskreys, J. Figiel, K. Klimek, K. Olkiewicz, M. Przybycien, P. Stopa, and L. Zawiejski, as well as engineers and technicians: J. Andruszkow, W. Daniluk, B. Dabrowski, P. Jurkiewicz, A. Kotarba, K. Oliwa, W. Ruchlewicz, W. Wierba, and A. Wlodarczyk. * D0 experiment at TEVATRON (FNAL), USA - two physicists: B. Pawlik and M. Przybycien from the Department were involved in this experiment. * Experiment PP2PP - two physicists: J. Chwastowski and B. Pawlik participated in preparation of detectors for the first run in 2002. In total, nine physicists and nine engineers and technicians were involved in carrying the above programs. The ZEUS experiment is a continuation of the investigation of e^±p interactions at the HERA collider which started over 10 years ago and has a perspective of another 5 years of activity. The upgrade of HERA and the expected 5-7 fold increase of luminosity makes the physical program very attractive. The Cracow group is responsible for the upgrade of the luminosity monitor to meet the new working conditions after the HERA revamp. The year 2001 was devoted to both the analysis of the data collected so far, and the intensive realisation of the luminosity upgrade system. After the luminosity upgrade of the Tevatron accelerator, the FNAL laboratory again collides protons and anti-protons at 1.8 TeV cms. energy in the so called Run II data taking period. The people from the Department were involved in the implementation of the new D0 component, the Silicon Multistrip Tracker. This includes participation in the activity of D0 Run II Monte Carlo Group and the Algorithm Group. The complete TESLA Technical Design Report became available in March 2001. There is an increasing activity of the Department physicists and engineers in the TESLA project. Two physicists from the Department participated in the PP2PP experiment (at RHIC in Brookhaven National Laboratory) in preparation for the first run in 2002. The experiment is devoted to the study of elastic pp scattering in the energy interval (50 - 500) GeV using both polarized and unpolarized beams, in the energy region so far not covered by any experiment. Data analysis from the two presently continued experiments (ZEUS, D0) cover the research program ranging from the exploration of the structure of the matter in photoproduction, deep inelastic e^±p scattering and (anti)pp collisions through the searches of the exotic and rare processes (W, Z, top, leptoquarks production) to the new approach to the traditional subject like properties of the pion emission source or properties of the hadronic final states. The above outsketched research resulted in 26 papers published in the renown scientific periodicals in 2001. (author)