  In this paper, we establish a boundary observability estimate for stochastic
Schr\"{o}dinger equations by means of the global Carleman estimate. Our
Carleman estimate is based on a new fundamental identity for a stochastic
Schr\"{o}dinger-like operator. Applications to the state observation problem
for semilinear stochastic Schr\"{o}dinger equations and the unique continuation
problem for stochastic Schr\"{o}dinger equations are also addressed.
