The study aims at developing a near infrared (NIR) tomography imaging system using a single rotating source/detector scanning device, which will be working for diffuse optical tomography (DOT) on medical applications. Some influential factors in terms of the design of this scanning device and test phantoms are investigated such as the temporal stability, air-absorption, container influence, and radiance normalization, etc. Then, a heterogeneous microsphere phantom with an off-center inclusion is investigated. It is observed that the radiance deviation between the heterogeneous and the homogenous is shifting with the inclusion position accordingly. Through the previously-mentioned system calibration, the back projection method as widely applied in the computed tomography (CT) technique is used to reconstruct optical images which indicate the distribution of optical property of the test phantom.