Current Issues in CP Violation

. A brief review of CP violation in K and B decays is given. While the observables " and Re(" 0 =") describing CP violation in neutral K decays do not allow a powerful test of the CKM mechanism of CP violation, rare K ! ß decays and in particular the B-meson system are much more promising in this respect. After a brief look at the K system, selected aspects of CP-violating effects in B decays are discussed. It is pointed out that combined branching ratios for B ! ßK modes, which have been observed recently by the CLEO collaboration, may allow to derive stringent constraints on the CKM angle fl that could open a window to new physics. INTRODUCTION The violation of the CP symmetry plays a central and fundamental role in modern particle physics. One of the reasons is that this phenomenon could guide us to physics beyond the Standard Model. To this end it is crucial to search for processes or relations among CP-violating observables that can be predicted in a clean way in the Standard..