Abstract: In order to facilitate the online application of stellar attitude determination system, a new autonomous star identification algorithm based on star pattern matching was presented in this paper. First, a new approach was proposed for describing the patterns of star image, and then the observed star pattern and the database of navigation stars patterns were constituted by using the star pattern description. Finally, the star recognition was conducted by comparing the observed star pattern vectors with an onboard database pattern vectors. Experiment results show that the proposed algorithm is very robust to the noise of observed star position. Also, it uses less computer resources and achieves faster calculating speed compared with the conventional algorithm.