Abstract: Our purpose was to evaluate two different reconstruction algorithms applied in micro-radiological imaging using synchrotron radiation.In our experiment,a bird feather was imaged by the synchrotron radiation and projections were acquired by high resolution X-ray camera.All equipments are supported by the Synchrotron Radiation Research Center located in scientific park in Hsinchu,Taiwan.In this work,filtered back-projection (FBP) and gradient-based maximum-likelihood algorithms (ML algorithm) were applied to reconstruct synchrotron tomographic images for comparison.An edge blurring is shown in results of the ML reconstructed image.Ring artifacts are more obvious in the image reconstructed by the FBP as compared to that of the ML algorithm.The FBP can do fast reconstruction,but the ML algorithm can reduce noise and artifacts.Thus,the two algorithms show very different characteristics.