To reliably prevent side shifts of a stabilizer with a simple and low- cost structure.

A side shift preventing device for a stabilizer comprises circular arc plate parts 12a arranged near to a rubber shoulder for fixing a stabilizer 11 to a vehicle body or the like to hold tight the stabilizer 11 therebetween each by roughly 180 degrees, and anti-shift flange parts 12b integrated with the circular arc plate parts 12a so as to project therefrom roughly perpendicularly to the longitudinal direction of the stabilizer 11. The plate parts 12a are integrally formed at their ends with fixing flange parts 12c for securing that tight holding.