Tritium time series for precipitation in Beijing have been reconstructed for the period 1953–2002 using various methods: Guanbingjun method; trend surface analysis method; double reference curve method; triangulation method; and correlation method. By comparing the reconstructed results with the measured data of Beijing as well as data of other regions available in the IAEA GNIP database, the corresponding tritium time series have been developed for Beijing for the period 1953–2002, and the optimal time series was selected. The reconstructed result can be used for groundwater dating and related studies in Beijing as well as the surrounding areas.