Optical Doppler tomography (ODT) is a non-invasive and non-contact imaging technology which combines Doppler velocimetry with optical coherence tomography (OCT) for measuring blood flow velocity and blood vessel distribution in highly scattering biological tissue. The principle of phase-resolved ODT based on digital Hilbert transformation is described and verified by measuring polystyrene solution flow velocity through glass capillary and microchannels of biochip respectively. With measurement for the Doppler frequency shift of the polystyrene flowing through glass capillary, the curve of the velocity of flow is obtained. The obtained images with high spatial and velocity resolutions, demonstrates that the developed ODT system has promising value for future clinical applications.