Chemical weathering is highly discontinuous and the discontinuity exists at the macro-scale, meso-scale and micro-scale.Macro-fractures are the main places of chemical weathering occurring. In weathering rockmass fresh rock blocks are surrounded and separated by corrosion zones. Water-rock reaction in Meso-fractures and pores between mineral particles determine the discontinuity of chemical weathering at the meso-scale. Mineral dissolution occurs preferentially in crystal defects and is discontinuous at the micro-scale. Because of discontinuity, chemical weathering can add water-rock interface and raise mineral dissolution rate. By way of spreading existing damages and accumulating weathering residue, discontinuous chemical weathering has the efficiency of separating, cracking rockmass, rock blocks and forming minerals, which may cause the rockmass mainly made up of fresh rock breaking away from the parent rock on a large scale. Chemical weathering affects rock blocks piling up the slope foot and brings them to split smaller rock and mineral debris that can be carried way by surface runoff. So, chemical weathering can promote remarkably slope planation landform evolution course.