Abstract: There are some water injection well with great high base gamma curve due to injection water for development in TUHA WENJISANG oil field. Interpretion error will be increased if we use normal radioactive logging technology, because statistic error of curve is much and curve amplitudes of preformatted sect is great smaller than that of abnormal base gamma curve. How do we log and interpret injecting profile of this kind of well? Through improving technology, we increase radioactive isotope intension and the amount of injection water. At the same time, through improving interpretation method, we amend curve amplitudes, thickness and interface of water injection layer. We must abolish a few indolent influence which comes from Rc integral circuit of gray apparatus because of high isotope intension, effect of logging velocity v and time constant τ are main.