  The different methods to derive the jet velocity and orientation on the
parsec scale are presented. From these methods I will discuss the velocity
distribution of parsec scale jets and the possible presence of acceleration or
deceleration in the jet velocity. Moreover, evidences of jet velocity
structures will be reported. Finally I will present new data on the
superluminal giant radio source 1144+35 to discuss in detail the properties of
pc scale jets.
