Reserch on crosstalk of flexible image fiber bundles. The theoretical expression on crosstalk is gotten. This paper describes a new technique to quantitatively measure crosstalk in coherent image fiber bundles using a calibrated optical video system. At the imput end of the fiber bundle, light is coupled into only one angle fiber. At the output end, a large area around the excited fiber is monitored using a video CCD array. Additionally, static MTF measurements to gether with visual inspection was used to correlate the crosstalk to the imaging properties of an optical fiber bundle. Comparison between different samples resulted by the experimental measurements.