In the talk, I will give conservativeness criteria for a class of Markov processes corresponding to lower bounded semi-Dirichlet forms.  I then apply these criteria to the case of symmetric jump processes,  which is a generalization of the previous works,  including the result by J. Masamune,  J. Wang and myself and the recent result by Y. Shiozawa. 

This talk is based on a joint work with Yoichi Oshima.