Abstract: Ultra-low ash coal( ash content <5.00%) is high quality raw material for ultra-pure coal.To obtain the optimum indices of raw coal for ultra-pure coal,the regional distribution and quality features of typical high-quality ultra-low ash coal in China was introduced in this paper.The washability and corresponding factors of typical low ash coals were studied using flotation de-ashing method under different granularity and chemical de-ashing method.The results show that most of the high-quality ultra-low ash coals,which mainly distributes in the northwest region in China,are low to middle metamorphic grade and difficult to medium grind coals.Compared with the inertinite-rich Nanlutian coal,the ash reduction of float coal from Taixi anthracite coal and Shendong coal are significant when they are grinded to size less than 6 mm or 0.2 mm.The flotation coal ash reduces 60.00% and 70.09% for the Taixi and Shendong coal with size less than 0.2 mm,respectively.After chemical de-ashing,the ash content is in order of Taixi coal