Protective effect of specimens with different w/c ratio, surface treatment methods, and protective time after dipping silane was studied by measurement of adsorption mass and Cl − content. The results show that: 1) the adsorption mass and Cl − content were decrease with protective time increasing, while its reduction degree was decline with the time up to 3 days. 2) There was no linear relationship between its adaptability to silane soakage and w/c ratio that the adaptability of specimens with different w/c ratio in order of decreasing size were as follows w/c=0.6, 0.4 and 0.5. 3) As for surface treatment, there was little difference about their effectiveness between air drying and vacuum drying, but the effectiveness of high-temperature drying is weakest.