Abstract: In order to instruct the design of interlayer of impregnated diamond bits and rock saws,the authors designed 4 kinds of shape and interlayer structure impregnated diamond blocks,developed and made the bit for experiment which can load and unload impregnated diamond blocks,and unfolded the experiment to study effect of the interlayer on ROP and wear extent.The phenomena and data of experiment showed:the interlayer is in favor of the improvement of bit stability.Main effect factors of ROP of impregnated diamond blocks are the thickness of interlayer,interlayer structure and shape,and proportion of the interlayer thickness,and mass fraction of diamond in interlayer.Penetration could be accelerated with the increase of the difference of diamond mass fraction between interlayers.Increasing properly of the thickness ratio of non-work interlayer is favor of promoting ROP.Main effect factors of wear extent of impregnated diamond blocks are thickness of interlayer,proportion of the interlayer thickness,and interlayer type and its diamond mass fraction.The more prominent the groove of wearing face is,the more wear extent is.