In order to explore the influence of the porosity change on the mechanical properties and energy dissipation of concrete materials in the construction of sponge city, we design concrete with porosity of 12%, 15%, 18% and 21% respectively. Uniaxial compression tests are performed on the four kinds of porosity concrete by using a universal testing machine. The stressstrain curvesis obtained from these tests. The following results are obtained by analyzing the test data: with the increase of porosity, the elastic modulus, peak stress and Poisson's ratio of concrete gradually decreased, and the peak strain increased gradually:with the increase of porosity, the total absorption energy and elastic energy of the concrete gradually decrease, and the dissipation energy first decreases and then increases. [ABSTRACT FROM AUTHOR]