The paper is dedicated to the analysis of a contribution of the distinction between states and contents of belief to the explanation of changes of belief in some specific situations such as changed stakes or evidence. The plausible idea about beliefs is that an agent may have two different beliefs in the same proposition representing different relations to that proposition - belief states. Different accounts of states of beliefs were proposed. The claim critically observed in the paper is that a change of belief may be explained as a change of either proposition believed or state of belief. It is argued that explanations of changes of beliefs in terms of changes in their states are reducible to explanations in terms of changes in their propositional contents. In particular it is argued that cases where changing beliefs are expressed by sentences with so called essential indexicals, which are considered to be cases of changing belief states, but not propositions, may be described as rather instances of changing beliefs propositional contents. There is also the account of belief as triadic relation between believer, believed propositions and mode of its presentation by believers. According to it belief change may be represented as a change of the mode of presentation which preserves propositional content of the belief. Against this account it is argued that modes of presentation of propositions either does not in fact contribute to semantic contents of corresponding beliefs or may be assimilated by their propositional contents. It seems plausible that to be relevant to the belief change the information is to be at least available to a competent reflexive agent of the belief , and this information then may be added to a propositional content of that belief after some reflection.