[Purposes] Due to long-term exposure to the atmosphere, the pH of the pore solution of geopolymers decreases induced by the carbonation, which leads to corrosion of structural steel. It is necessary to analyze the pH of the pore solution of the system after geopolymerization.[Methods] Considering both normal temperature and high temperature curing methods, the pH of pore solution under different contents of activators were measured. The correlation was explored by reaction degree test, mercury intrusion porosimetry test（MIP） and scanning electron microscope test(SEM). The effect of activator content and curing temperature on pH of pore solution analyzed. [Findings] The pH of geopolymer pore solution was related to the hydration reaction. At the early stage of curing, the OH- was consumed in reaction process, resulting in the continuous decrease of pH of pore solution. With the extension of curing time, the reaction slowed down, and the pH values of pore solution tended to be stable. The test of reaction degree and microstructure indicated that the dissolution and polymerization of metakaolin can be promoted by increasing the content of activator, which improves the microstructure of geopolymer, and reduces the pH of pore solution after reaction. [Conclusions]?Curing at high temperature is beneficial to the early solidifying of geopolymer. The dissolution of raw materials in alkaline activators will be accelerated.however, the OH- ions will be further consumed in the system, reducing the pH of the pore solution.