A fiber-typed optical coherence tomography (OCT) based projected index computed tomography (PICT) system is reported. A water-filled glass tube with outer and inner diameters of 1.3 mm and 0.9 mm respectively is measured by the developed system. 180 projection data from the sample rotated at step resolution of 1 degree are collected, and its refractive index mapped image is then reconstructed based on convolution back projection algorithm. Experimental result with high spatial resolution shows that air, glass and water with different refractive indexes are properly discriminated and their boundaries are clearly resolved. Meanwhile, due to the utilization of information on refractive index distribution, geometrical distortions usually observed in conventional OCT images are avoided in the PICT image.