The Multi-angle Imaging SpectroRadiometer (MISR), recently launched on the NASA Terra platform, is designed to provide high-resolution observations at nadir and eight oblique viewing angles. We have developed a new method to retrieve both the horizontal and vertical distribution of marine trade cumulus clouds from MISR observations. Because MISR stereo imaging can be used to compute cloud top, height, this new method allows us to completely specify the 3D geometry of the clouds. This method has been tested for a single MISR overpass of Nauru island (August, 2000). Here we will present results of further testing over additional MISR scenes. We use these scenes to derive frequency distributions of horizontal and vertical cloud size. Results of the statistical relationship between the horizontal and vertical cloud sizes will be presented as well.