Abstract: According to the actual mining conditions of the Bayan Obo open stope,combining of the currently ride valid data, the line density, aperture, hole pitch are used to do some research on the influence on splitting blasting under the same topography and geological conditions. The relationship between these parameters and the influence on splitting blasting respectively is analyzed.The experiment show that, in order to obtain the better effect of the slope splitting blasting, the smaller aperture, hole spacing should be used, and the inclined hole same as the design side slope rate should be adopted as much as possible.At the same time, the control of drilling quality must be pay more attention.

Key words: The open pit, Pre-splitting blasting, loading density, Aperture, Hole pitch