Abstract:Two importantproperties of hierarchical concept lattice were presented: the concepts in a same layerare incomparable and a concept isoverlayed by at leastone concepton the upper layer. The general formula for the object and atributemappingwas derived, and a theorem, which describes the structural invariability of objects during their construction, was obtained. A new algorithm was proposed to construct the concept lattice occording to the properties and theorem. The proposed algorithm constructs the lattice lay by lay based on the hierarchical structure of concept lattice. No abundant concept is created, because filtration is carried outduring construction of concepts.