The large subunit ribulose-1, 5-bisphosphate carboxylase/oxygenase (rbcL) is a gene cluster directly related to photosynthetic carbon fixation and because of its important biological functions, the structure and evolution history of rbcL is of great interest to world's scientists. To elucidate the evolutionary history of rbcL, the rbcL genes from 7 kinds of algae of Laminariaceae and 6 kinds of algae of Alaruaceae were selected. Then the phylogenetic relationships were explored by neighbour-joining and minimum-evolution methods. Based on two kinds of phylogenetic analysis, we knew that rbcL evolutionary changes occurred in the early stage, but it's followed by a period of evolutionary stability. The conclusion will provide guides for further research on rbcL evolution history of other algae.