  The dual basis of the canonical basis of the modified quantized enveloping
algebra is studied, in particular for type $A$. The construction of a basis for
the coordinate algebra of the $n\times n$ quantum matrices is appropriate for
the study the multiplicative property. It is shown that this basis is invariant
under multiplication by certain quantum minors including the quantum
determinant. Then a basis of quantum SL(n) is obtained by setting the quantum
determinant to one. This basis turns out to be equivalent to the dual canonical
basis.
