The osmotic coefficient by clear water and sewage, static adsorption, dynamic and water penetration tests were conducted to determine the parameters, which including materials matching, hydraulic loading, and wet to dry ratio, in the treatment of sewage from highway service area (SHSA) in Chongqing by ecological soil system. The results showed that, according to principles of easier getting, high and stable hydraulic load, large decontamination capability, the materials matching of working layer SHSA was made of 30.67% soil, 61.33% sand and 8.00% cinder in Chongqing, and the supporting layer was consisted of 0.20 m cable and 0.10 m broken stone (height). The total height of the ecological soil system was 1.6 m, at which 1.00, 1.20, 1.40, 1.60 m department of hydraulic loading were 0.344, 0.322, 0.307, 0.298 m x d(-1), respectively. The flooding period of working layer was 1 d and the drying period 1.5 d, i. e, the ratio of wet to dry was 1:1.5.