A crystal lattice is the basic structure of many solid materials, such as metals, semiconductors, and insulators. Modeling of crystal lattices can be used for research of existing and simulation of new materials, study of crystallization processes. Constructive-synthesizing modeling tools are used to model crystal lattices. That uses the attributes of the elemental base, which allows to naturally build fractal spatial graphs according to the rules of substitution. It becomes possible to specify which vertices of the graph and to which graph should be changed at each step of graph generation. Crystal lattices are considered as partial cases of fractal spatial graphs.