Galectin-1(Gal-1), a carbohydrate-binding protein with an affinity for β-galactoside, is widely expressed in various normal and pathological tissues and it also plays an important role in regulating immune cell homeostasis and tumorigenesis. This study investigated the effects of restraint stress on serum Gal-1 by Western blot analyses and enzyme-linked immunosorbent assays. The Gal-1 levels of the restraint-stress group were significantly higher than those of the control group. However, this increase by stress was not obvious in adolescent rats. The pattern of these changes was similar to that of corticosterone. Furthermore, this Gal-1 increase in the serum was prevented by pre-treatment with a neurotoxin 6-hydroxydopamine (6-OHDA), which destroys the noradrenergic nerve terminals. However, a bilateral adrenalectomy (ADX) had no effect on the Gal-1 increase. These results suggest that Gal-1 is a candidate stress marker protein and that the stress-induced increase of Gal-1 in serum is regulated by the sympathetic nervous system under stress conditions.