We have. studied nonlinear flow behavior of entangled DNA solutions using particle tracking velocimetry in Couette and cone/plate geometries. At apparent shear rate gamma(app) < 0.1 s(-1), the velocity profile is linear across the gap. Beyond the terminal region with a,p < 40 s(-1), the velocity profile becomes temporarily banded after the stress maximum and shows massive wall slip at long times with little shear banding in the bulk. At gamma(app) > 40 s(-1), the velocity profile progressively curves and becomes banded with a sharp interface after hundreds of strain units. In the steady state, the thickness of high-shear band increases linearly with the apparent shear rate. At gamma(app) = 1000 s(-1), the velocity profile returns to linearity.