Energy and environmental crisis has leaded to many alternative eco-energy researches world widely. This research has surveyed small fishery boat populations which are incessantly affected by the fuel price. Researcher focused only on the 6-cylinder diesel engines which had higher fuel consumption. The result found that HINO engines were typically used. Consequently, the experiment was conducted on a 6-cylinder HINO diesel engine fuelled with biodiesel B 5 and B 20. The tested fuels in this research were certified by Department of Energy Business. The results show that biodiesel B 20 give lower torque, power and efficiency than that of biodiesel B 5 by 2.12%, 2.40% and 2.38% respectively. However, biodiesel B20 shows very apparent advantages in term of CO, HC, NOx and PM emissions. The reductions are 36.92%, 11.76%, 19.71% and 3.86% respectively. The result reveals that biodiesel B20 has a compatible potential to biodiesel B 5 and can be consider as one of the environmental friendly alternative fuel.