Abstract: accoding to the practical demand of the geologica guidance to the rlling along the seam in the underground mine, an azinuthganmma logging tool while drilling was designed and developed and could provide strata gamma parameters to the geologic guidance engineering With the analysis on the measured performance features while drling in the underground mine and the natural gamma logging principle,fom the hardware software and structre aspecs,an azimuth gamma logging to while drllng to delect the upper and lower drectional gamma parametrs was designed and realized.The intrument tests were conducted in the surface exporation hole and the real hole in the underground mine.the measured data were stable and resuts were reliable. n the difrent radioactive strata,gamma measured vaueswere diferent obviously nd the top and low gamma measured values would be varied reguiarly during the driling operation in the boundary secion.The results showed tat the azimuth gamma logging nstrument whiledriling could meet therequirements of s isnic ftorsion and water pressure of the measurement wrile ling. The top and low gamma measured results could serve the geologic guide engineering and guide the drilling along the seam