Comparing with conventional expressway embankment filled with clay only, the sand embankment tipped by intensely-weathered rock (IWR) can effectively reduce the consumption of cultivated land resource caused by the construction of expressway engineering. So it is significant to research the constructions of sand embankment tipped by IWR if local sand resources are enough. Combined with the construction of Qing-Lin freeway, in China, the slope stability of the embankment filled with sand and tipped by IWR outside was analyzed in the paper, and the analysis was conducted by the strength reduction method. The effects of the changes of compaction, water content, ratio of slope, height of the embankment and different IWR-width on the safety factor of the slope stability were investigated. The results indicate that, when the height of embankment is constant, the ratio of slope is the most important factor which influences the stability of side slope, and the IWR-width does not have a decisive effect on the safety factor on subsoil condition and it can be determined according to the convenience of site construction.