The two sponges—H. perlevis and the Axinella sp., have been extensively studied for the development of in vitro sponge cell cultures for the potential production of bioactive metabolites. This chapter has summarized and synthesized the work done in our group, mainly covering sponge cell separation, cell identification, primmorphs culture, and cellular localization of the bioactive compounds. These two sponge species significantly differ in habitat, appearance, living strategy, cellular constituents, and cellular features, making them very representative of different challenges and strategies to establish a cell culture system. While a certain degree of success has been achieved in developing in vitro cell culture for both sponge species, developing a continuous cell line that can be readily scaled up for bioactive metabolite production remains challenging. The critical data summarized here could provide some information and insights for sponge-related research, including sponge biology, cell biology, molecular biology, and sponge biotechnology.