A variety of successful research on Palm Methyl Ester or Biodiesel reveals that Biodiesel contributes substantial reduction of Particulate Matters (PM) emitted from Compression Ignition (CI) engines due to the impact of effective oxygen function compared with commercial diesel. To reduce further PM emission, oxygenated fuel such as ethanol could be one of the possible options. This research will focus on the effects of ethanol on PM quantity and morphology by blending it with biodiesel. In the experiment, Ethanol will be blended with biodiesel (B100) with the blend ratio of 10%, 20%, and 30% by volume and then operated with a small CI engine in order to investigate PM development. Operating conditions will be divided into 0%, 20%, 40%, 60%, and 80% load of maximum torque. For each operating load, the engine speeds will be varied into 1600, 1800, 2000, 2200, and 2400 RPM. The PM quantity from each engine condition is measured by 3 aspects; PM intensity collected by opacity smoke meter, PM mass trapped at the filter, and filter pressure difference due to the trapped PM. The PM nanostructure images are investigated by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Both PM size and size distribution are measured by Particle Size Analyzer with Laser Diffraction technique and reconfirmed by image processing method. The results from this research might be utilized as basic information for Diesel Particulate Filter (DPF) development for ethanol-blended biodiesel fuel.