We use data collected by the displaced track trigger of the CDF
Run II detector at TeVatron to measure the B mesons lifetime in the hadronic
decays: b+(u) --> D0 pi+, B(d) --> D-/+ pi++/-, B(d) --> D-/+ 3 pi+, B_s -->
D-/+_s pi++/-, B_s --> D-/+_s 3 pi+. Recent developments in the measurement
of the lifetime of the charmless B_s --> k+ k- mode will be presented.