Intertidal rocky shore is one of the most vulnerable ecosystems facing global change.Based on long-term environmental monitoring and modelling predication,most coastal areas in China have had and will continuously suffer from global warming,ocean acidification and extreme climate events.Furthermore,with the development of coastal economy,more and more artificial structures,including harbors,dams and bridges etc.,are constructed along the China coast.These artificial structures,especially architectures on the muddy shore,will provide suitable substrate for rocky shore species,and potentially play crucial roles as step stones for species distribution shifts.There are clear biogeographic barriers for some rocky shore species along China coast.Phylogeographic studies were carried out in some widely distributed intertidal limpets and snails,and populations along the China coast could be divided into southern and northern groups with Yangtze River estuary as a barrier.The formation of the barrier is due to multiple factors,including historical events,ocean current,freshwater discharge and substrate.One of the most important factors for the formation of the barrier is the unsuitable substrate in the Yangtze River Delta.Along the coast of Jiangsu province,there are extensive large scale muddy shores,which possibly hamper the larval dispersal and settlement of rocky shore species.However,the recent large-scale land reclamation and dam construction in Yangtze River Delta provides possible settlements for rocky shore species.Phylogeographic studies show that these new habitats are occupying rapidly by alien populations from both directions,and provide step stones for species migration between southern and northern populations,especially for southern populations which will potentially experience poleward distribution shift in the scenario f climate change.