It is commonly recognized that micro behavior near the interface have considerable significance in the understanding of the mass transfer mechanism in two phase processes. In this work
two dimensional laser doppler anemometer technique has been employed to investigate the hydrodynamics and turbulent structure near the interface of a moving bubble. In our experiment
a bubble was fixed in a specially designed gas-liquid channel with the liquid phase flowing down from top to bottom so as to keep the bubble stationary. It was discovered that in the center of the bubble wake near interface the tangential velocity exhibited large scale coherent structure caused by Karman vortex shedding and the normal velocity showed more stochastic behavior than the tangential. In the edge of the bubble wake
both tangential and normal velocity consisted of the large scale coherent and stochastic vortex. The time averaged normal velocity near rear interface diminished from center to edge of the wake
but the tangential one showed only a little change. The integral scales near rear interface changed appreciably
having maxima in the center of wake and minima in the edge with micro scales remained unchanged. Near the frontal interface
both the tangential and the normal velocities presented regular vibration with the same frequency as the Karman vortex shedding in the bubble wake
while the integral and the micro scales exhibited the same behavior as in the rear interface. The present study on the turbulent behaviors near interface may provide some basic information for understanding the mass transfer mechanism and efficiency in two phase processes.