Abstract: The detemination of local blood flow in brain gray matter (rCBF) using the type CGEM 2000 ~(133)Xe encephalography is a reliable indication for judging the degree of lack blood disease. For all the inspected patients the scalp analogy localization is used. 28 probes are applied to some regions of the forehead, the vertex, the temporal folium and the occipital folium. The localization is a ccurate and repeatable. The result of rCBF determination is similar to XCT, but its range is rather wider than XCT. Therefore, the rCBF determinationinin in clinic diagnosis is reliable. It can give the rCBF value qualitively, it can be used not only for diagnosing the desease in brain, but also for the predication before apoplexy, especially for vertigo disease to be inspected. For the vertigo disease of middle age and old man, the first consideration should be the decreasing of rCBF value. For the inspection of thrombus of neck artery system, it can reflect the real range of pathological changes correctly. The method is superior to XCT for treatment planning, estimating the results, supervising the effect treatment, and the diagnosis of acute cerebral embolism. In our country, the morbidity rate, the sicknes rate, the disability rate and recurrent rate of cerebrovascular disease are very high, especially for the old man. In the paper, using type CGEM 2000 cerebral angiography technique for the screenning, satisfactory results for 1010 cases altogether are obtained.