The transmitter frequency and the spacing of induction logging tool are main factors of determining the matching degree between the well logging data and the investigated stratum. Improper selection of transmitter frequency and spacing will make investigation depths overlap which reduces the real stratum information. It will also bring about bad nfluence on the tested apparent parameters and make the inverse problem more complex. For logging tool, if its vertical resolution is high, its investigation depth is relatively not enough; but if its investigation depth is deep, its vertical resolution is relatively low. So it is very difficult to synchronously satisfy the requirement of investigation depth and vertical resolution.According to the theory of geometrical factor, this paper analyzes the relationship of transmitter frequency and spacing with investigation depth and resolution. Based on Russian logging tool VLKIZ, this paper absorbs the advantage from European and American EPRL tool and presents a novel design of lowering transmitter frequency, shortening spacing of the tool and measuring amplitude ratio and phase shift of the receiver signal synchronously. Now we are working on the simulation. We believe optimistically this new design will makes the investigation depth and the resolution satisfy our requirement well. 方法确定发射频率和感应测井仪器研究测井仪的改进间距