We have developed an electron-tracking Compton camera (ETCC) for new medical imaging device. Conventional gamma camera, PET and SPECT, have the problem of energy limitation. This problem is one of the major problems for this study. However, our ETCC has a wide energy dynamic range (200-1300 keV). Also ETCC have the wide field of view because ETCC does not need a collimator and does not need to catch two gamma rays which produced by the annihilation process. In this paper, we show the results of imaging result of the 3-D which have imaged only one direction using one head camera. And we have developed the two-head ETCC. Two-head ETCC have a good efficiency and spatial resolution. © 2010 IEEE.