Summary: This paper solves the problem of transforming the initial context-free grammar (CF-grammar) without excess characters into equivalent CF-grammar with less complexity. To solve this problem, the following relation on the set of a CF-grammar non-terminals is introduced: \(E = \{(X,Y): (X=Y) \vee (X\to \alpha\Leftrightarrow Y\to \beta \wedge\vert \alpha \vert = \vert \beta \vert \wedge \forall i\,(\alpha (i) = \beta (i)\vee (\alpha (i), \beta (i))\in E))\}\) where \(X\), \(Y\) are non-terminals, \(\alpha\), \(\beta\) are chains of terminal and non-terminals, possibly blank, \( \alpha (i)\) is the \(i\)-th character in chain \(\alpha, \beta (i)\) is the \(i\)-th character in chain \(\beta \). It is proved that the relation \(E\) has the equivalence property and splits the set of non-terminals into equivalence classes. An algorithm is proposed for splitting a set of non-terminals into equivalence classes based on the method of sequential decomposition of the set of non-terminals into subsets so that non-equivalent non-terminals fall into different subsets. New CF-grammar is built on a set of non-terminals \(N\), which elements are representatives of equivalence classes. From the set of rules of the initial CF-grammar, the rules with the left parts belonging to the set \(N\) are chosen. If there is a non-terminal in the left side of any selected rule that does not belong to the set \(N\), then it is replaced by its equivalent non-terminal from the set \(N\). After such transformations in the CF-grammar, sets of identical rules may appear. From each set of identical rules, we leave only one rule. The result is a CF-grammar containing less rules and non-terminals than the initial CF-grammar. The paper provides an example of the implementation of the described transformations.