Two-dimension and three-dimension topography of pulsed lasers ablation of tissues were scanned by means of optical coherent microscopy, in order to analyze the ablation characteristics of pulsed Erbium:YAG lasers for hard biological tissues. Experimental results indicate that under the same laser parameters, ablation efficiency for gall-stone is higher than that for urinary stone. The higher the intensities of pulsed lasers are, the higher the ablation efficiency will be for both gall-stone and urinary stone. The higher ablation efficiency mainly embodies that wider surface diameter, deeper height, and bigger volume for craters will be obtained. Measurements for stone craters using the optical coherent microscopy are higher by about one order than those using the optical coherent tomography. Optical coherent microscopy system can contribute to quantitatively measure hard tissues irradiated by pulsed lasers much better than optical coherent tomography system.