Abstract: In order to develop a new type of oil supplying system to replace the traditional pump pipe nozzle system, the injection characteristics of common rail accumulator electronic unit injector are studied. The flux characteristics, injection pressure characteristics and injection timing are experimented with the developed apparatus, the influence of different factors on the injection characteristics is analyzed according to the experimental results. The results demonstrate that not only common rail pressure and accumulator time but also rotation speed can influence the characteristics of common rail accumulator electronic unit injector. In respect of flexibility of regulating injection characteristics, the electronic unit injector is much better than that of traditional pump pipe nozzle system.