We introduce a new method to test the three coexisting theories (neutral theory, niche partition, demographic niche differentiation) in field, and apply it to a rocky intertidal community at regional level. First, we obtained 55,944 transitions from a 12-seasons record of species occupancy of fixed points in space on 25 rock slopes locating on Hokkaido. Based on the data, we calculated resource-use patterns which reflect niche traits and demographic traits of each species. In addition, we assigned parameters to the regional dynamics equations of neutral theory using the same transition data, then compared demographic traits of each species with that from neutral assembly (a test for demographic niche differentiation). Furthermore, we compared the resource-use pattern of each species with that of neutral assembly which was obtained by putting occurrence value in the transition matrix of the parameterized neutral community (a test for niche partition). The observed demographic traits and resource-use patterns poorly followed that predicted by the neutral theory but well followed by niche partition or demographic niche differentiation. These findings indicate an essential role for variation in species property for coexistence in the metacommunity.