Superstring theory includes a lot of massive higher spin excitations, and there would appear a higher spi gauge symmetry at the tensionless limit. Moreover, it has been expected that these states could be described by a broken phase of higher spin gauge theory. Recently, it becomes possible to discuss the realizations of the idea with the help of Vasiliev theory and AdS/CFT correspondence. In this talk, I will explain recent developments on the concrete relation between higher spin gauge theory and superstring theory by making use of AdS/CFT correspondence. In particular, I will focus on the AdS_3 case. Moreover, I will show that higher spin fields become massive due to the braking of higher spin symmetry using a simple example.