Abstract: The cutting roadway， the broached groove of oblique blasthole and both ends retreat mining of the induced caving method was proposed due to difficult stope preparation and cutting engineering， poor stope safety conditions and high loss and dilution of the steeply inclined and fractured medium thick orebody in Shuangyashan iron mine. The suitable parameters to induce orebody caving were given. The caving process and the lumpiness of caving block were analyzed and the loss rate and dilution rate of caving ore were estimated based on the No.S5 stope in Shuangyashan iron mine. According to results of the regular shift recordings， the recovery rate was higher and the degree of the caving block was good in early recovery period， which was consistent with previous analyses. The rock mixing rate increased along with cycle changes after complete caving， and the phenomenon was associated with the position of the drilling of roadway and the lumpiness of blasting blocks. The recovery indexes of this method are good and the mining problems of the steeply inclined and fractured medium thick orebody can be effectively solved.

Key words: steeply inclined and fractured medium thick orebody, induced caving method, ore loss rate, ore dilution rate, ore lumpiness