The local gas holdup details and behaviors in the cylindrical split airlift column by using an unconventional gamma-ray densitometry (GRD) measurement in non-invasive manner technique was investigated for the first time in this work for such kind of airlift column. With different gas velocities, 1, 2, and 3 cm/s, at three various axial planes (different levels) in z = 3, 60, and 110 cm were studied for local distribution in radial gas holdup profiles. The distribution in gas-liquid phases (air-water system) in the entire split reactor column, in the rising and descending sides, including their behavior in the upper and lower zones of the split plate, were investigated as well. The results of this study showed that approximately all reactor zones had exemplary gas-liquid phases and that there was a large magnitude over both the dividing ring and the top sections. The results further indicated that the distribution of which flow variable in the implementation of the cylindrical split reactor can have an important impact on its behavior, especially for cultivating applications of microorganisms. These data can be used as benchmarks results for CFD simulations and validation.