Abstract: Abstract: Accurately estimating the development of concrete compressive strength and avoiding suffering from negative temperature before concrete compressive strength reaches the frost-resisting critical strength is an important issue for concrete construction in the Qinghai-Tibet Plateau. When predicting the strength of concrete based on the traditional maturity method, there exists low prediction accuracy because the apparent activation energy is treated as constant value in the entire process of forecasting strength. In fact, the apparent activation energy value is influenced by many factors, such as curing temperature, degree of hydration and type of cementitious material. There is not any unique value that can precisely predict the concrete strength throughout the curing period. In view of the above shortcomings, an improved maturity method is proposed through modifying the determined value of apparent activation energy. And the specific methods are as follows: Firstly, according to the typical service environments of concrete structures, the durability requirements of the environment for the concrete are determined, and then the predicted target strength and the corresponding prediction range can be determined. Secondly, 3 temperatures are selected to maintain the concrete at a constant temperature, one of which is the standard curing temperature (usually 20 ℃). The compressive strength of concrete at different ages under different curing temperatures is tested. By assuming apparent activation energy values, the test ages at the other 2 temperatures except the standard curing temperature are converted to the ages under the standard curing temperature. Then the apparent activation energy and the corresponding parameters in the strength-age curve are obtained when the error between the actual strength and the predicted strength of the concrete within the range of target strength is minimized. At last the calculated parameters are utilized to predict the concrete strength at different ages. In order to verify the accuracy of the modified method, 4 groups of concrete with different mixing proportions were designed and were cured under 3 constant temperatures (5, 20 and 35 ℃ respectively). Meanwhile, one group of concrete with fly ash (F10) was subjected to variable temperature curing. The design of curing temperature refers to the characteristics of ambient temperature in the Qinghai-Tibet Plateau. The compressive strength of concrete with different ages was tested and the traditional maturity method and the modified maturity method were respectively used to predict the concrete strength within the target strength range. The results show that among the 24 groups of predicted values of the compressive strength of the concrete in the target strength range using the traditional method, the error between the predicted and measured values in the 20 groups is more than 10%, and the predicted value is generally greater than the measured value. When using the modified maturity method, there are 30 groups whose prediction errors for the target strength are lower than 10% in 36 groups, and the accuracy of the strength prediction is improved remarkably compared with the traditional maturity method. Thus, this improved method can be used to predict the strength development of concrete in the Qinghai-Tibet Plateau to prevent early-freezing of the concrete.