To solve the problem of clustering this paper proposes a concept of temporal density, which reveals a set of mathematical properties, especially the incremental computation. A clustering algorithm named TDCA (temporal density based clustering algorithm) with time complexity of O(c×m×lgm) is created with a tree structure implemented for both storage and retrieve efficiency. TDCA is capable of capturing the temporal features of a data stream with skew data distribution either in real time or on demand. The experimental results show that TDCA is functionable and scalable.