I will talk on the analytic characterizations of gaugeability for generalized Feynman-Kac functionals including continuous additive functional of zero quadratic variation in the framework of symmetric Markov processes.Our result improves the previous known work on the analytic characterization due to Z.-Q.Chen even if we restrict ourselves to deal with non-local perturbations.We also prove that such a characterization is also equivalent to semi- conditional gaugeability and to the subcriticality of the Schroedinger operator associated to our generalized Feynman-Kac semigroup under the semi-conditional Green tightness of related measures.We also give the characterization of the conditional gaugebility under the conditional Green tightness of related measures and a suitable condition.This is a joint work with Daehong Kim.