In the present paper, some turbine wheels produced by metal injection molding (MIM) were subjected to x-ray inspection using different three x-ray equipment. An x-ray inspected turbine wheel was then cut and polished to observe defects by OM and SEM equipped with EDS. The defects existing in the blades and the center of the turbine wheels were analyzed statistically using MINI TAB software. The results show that, under the same testing condition, the film x-ray equipment has higher sensitivity than the real-time imaging x-ray. However, the microfocus x-ray testing is not suitable to the MIM418 turbine wheels due to low power. NDT and metallographic observation exposes that Maro-cracks are prone to forming in the center part of the turbine wheel, and the mi-cro-defect in term of porosity in the blade is higher than that in the center of the sintered turbine wheel, and decreases significantly after heat isostatic pressing (HIP).