In order to explore mix design method of porous ecological concrete, the paper analyzed the strength and porosity of porous ecological concrete on the basic of orthogonal test method, through experimental study. The result showed that the observed porosity was on the rage of 13.8% to 31.5%, the average was about 25.24%, which was near to the target value. However, the observed compression strength was about 3.49 to 18.2MPa, the average was about 9.75MPa, which was just the theoretical values 9.21%to 48.02%.According to the test, when the porosity was over 20 percent, strength would be rapidly decreased .When the porosity was 31.5%, the strength was just 3.49MPa, which was far lower than the target value. The test also showed that the strength and porosity were also affected by ash set ratio. The bigger the ash set ratio, the higher compression strength, but the porosity would low. This could explain that the existed strength theory was not fit to the mix design of porous ecological concrete. According to the experimental results, it has established the empirical formula（4）and formula（5） about compressive strength and porosity design through regression analysis. The empirical formula can guide mix design of porous ecological concrete.
