  It has been shown recently that the toroidally compactified type IIB string
effective action possesses an SL(2, R) invariance. Using this symmetry we
construct an infinite family of macroscopic string-like solutions permuted by
SL(2, Z) group for type II superstrings in $4 \leq D < 10$. These solutions,
which formally look very similar to the corresponding solutions in $D = 10$,
are characterized by two relatively prime integers corresponding to the
`electric' charges associated with the two antisymmetric tensor fields of the
strings. Stability of these solutions is discussed briefly in the light of
charge conservation and the tension gap equation.
