Recent CP asymmetry measurements in tree-dominated processes, $B^0\to π^+π^-, ρ^+ρ^-, ρ^{\pm}π^{\mp}, B^+\to DK^+$, and in penguin-dominated decays, $B \to π^0 K_S, η' K_S, ϕK_S$, are interpreted in the framework of the Kobayashi-Maskawa (KM) mechanism of CP violation. The KM phase emerges as the dominant source of CP violation in tree-dominated decays, which are beginning to constrain the unitarity triangle beyond other constraints. Improving precision of CP asymmetry measurements in penguin-dominated decays may indicate the need for new physics.

Talk presented at the Sixth International Conference on Hyperons, Charm and Beauty Hadrons, IIT, Chicago, June 27--July 3 2004