The aim of the paper is to shed light on the problem of identity of particulars over time within the framework of Quinean analysis. First, it focuses on the relationship between essential and accidental property changes as a criterion for distinguishing cases when objects retain their identity from cases when they loose it. In this part it is shown, that a coherent distinction between essential and accidental properties is problematic. Quinean approach indicates that we do not need to look for any kind of criterion of identity of particulars over time. Hence, the conclusion is that the identity of particulars over time should not be viewed as a problem of how to understand the concept of identity, but rather as a problem of how to understand certain general concepts, i.e. how to individualize certain parts of the world by the use of certain general terms.