Abstract：The use of environmental isotope of tritium to establish the quantitative model of groundwater flow has been widely applied in the field of hydrogeology and environmental monitoring. Zhang Yanhong et al. developed 'MGMTP'(modified global model of tritium in precipitation) to provide a new method for the quantitative study of tritium concentration in the global scale, but the tritium model is now facing a problem of limit period and predicts negative values for the year after 1990. In this paper, we used the dataset over the period from 1960 to 2014 provided by the International Atomic Energy Agency and World Meteorological Organization (IAEA&WMO) to extend the time period of MGMTP model based on factor analysis. At the same time, we also compared the difference between data preprocessing and analysis methods. The problem of negative values predicted by MGMTP model mentioned by Zhang et al. was further clarified and fixed. This extended MGMTP model was applied to the typical stations of the northern and southern hemispheres. The results showed that it can well calculate the annual mean tritium concentration in precipitation over the world from 1960 to 2014, which is especially necessary and valuable for the area with few or without the monitoring data.