To analysis the absorbing function of forest in the single pinus forest, we measured the concentration of pH, EC cation and anion about the collected rainfall, stemflow, throughfall, soil solution and streamwater. We also described a mechanisms and process that affect the rain water which flows into the soil, when it reaches forest area through the bodies of trees. The pH of stemflow (6.33) was figured out the lowest value, as pH of throughfall (5.83), also lower compared with that of rainfall (6.03). The EC of stemflow (110μ S/cm) and throughfall (63μ S/cm) showed a higher value, compared with that of rainfall (37μ S/cm). Density of Ca^<2+> showed the highest values among the cation and the results showed that Ca^<2+> concentration of stemflow and throughfall were affected by Ca^<2+> concentration of rainwater. Generally, concentration of anion was higher than that of cation, showing high values in the throughfall and soil solution.