Abstract: Based on the ecophysiological development processes of spring maize and the principle of the physiological development time for specific type of crops at a given development stage being a constant, a simulation model for spring maize developmental stages was established by the scale of physiological development time. In the published methods for determining crop physiological development time, only the daily thermal and photo-periodical effectiveness is considered, and some specific genetic parameters are introduced to adjust the genotypic differences. However, it is difficult to gain these parameters in real time in large regional scale when simulation model comes into use operationally. In this paper, the physiological development time during the development stages of spring maize was determined based on the climatic suitability, with the joint effects of sunlight, air temperature, and precipitation on the crop development processes considered. The validation of the model with the data from the agro-meteorological observation stations in Northeast China in 2009 and 2010 indicated that there was a high goodness of fit between the simulated results and the observed values. The correlation coefficient between the simulated results and observed values was over 0.84 in vegetative growth stage and over 0.77 in reproductive growth stage. Moreover, the root mean square error (RMSE) between the simulated results and the observed values during the whole crop growth period was 3.8 days. Therefore, this model was relatively robust on mechanistic explanation, had high operability, and could be applied to simulate and predict the date and duration of different growth stages of maize in agrometeorological information service.