The measurements of oil properties of crude Jatropha oil and its blends of 10%, 20%, 30%, 40%, and 50% with diesel fuel have been carried out in this study. Our results suggested that the viscosities of crude Jatropha oil (CJO) blends decrease gradually with increasing temperatures, but they increase gradually with rising ratio of crude Jatropha oil compared to those of diesel fuel. Analysis of physical properties suggested that cold filter plugging point, calorific value, gravity and cetane index decrease gradually with rising percentages of crude Jatropha oil, but the flash point and mid boiling point increase gradually compared to those of diesel fuel. In this study, the prepared oil blends are applied to a power generator for a real application test. Results of electricity generation suggested that crude Jatropha oil blends may be used as an alternative fuel compared to that of diesel fuel. Results of gas emissions in a power generator suggested that CO, CO2 and NOX emissions from crude Jatropha oil blends are lower, but O2 emissions are higher compared to those of diese fuels.