Abstract: Continuous daily observations over as long a period as possible are an important basis for the study of extreme climate events and their characteristics over the past hundred years. Due to the scarcity of reliable and continuous daily observations over century-long scale, the pattern of extreme climate change before the 1950s still can not be well interpreted both in China and abroad. New series of daily maximum and minimum temperature observations for Beijing from 1 January 1841 (for minimum) and 1 January 1880 (for maximum) to 31 December 2019 have been constructed. Two daily observational datasets are obtained from China Meteorological Administration (CMA) as the basic sources: (1) The digital daily observations covering the period of 1 January 1841—31 December 1950 from 5 in-situ sites and (2) the daily data observed by new weather and climate systems over the period of 1 January 1951—31 December 2019. Errors caused by manual observations, instrument malfunctions and digital inputs are removed by quality control. Those missing daily maximum and minimum temperature data before 1951 at Beijing meteorological observation station are filled by interpolations using standardized series method. Several significant breakpoints caused by changes in station locations and instrument manufacturers are detected by penalized maximal t test (PMT) and penalized maximal F test (PMFT). The homogenized daily maximum and minimum temperature series for Beijing are obtained by Quantile Matching (QM) adjustment with reference series from Berkeley Earth-daily data. It is found that the decadal variabilities of the new daily temperature series over century-long scale are consistent with those of Berkeley Earth-monthly, CRUTS4.03 and GHCNV3 data in Beijing. The warming trend estimated based on the annual mean temperature series averaged from the new daily maximum and minimum temperatures is 0.154±0.018°C/(10 a) (at the 95% confidence level for statistical uncertainties) during the period of 1911—2019 in Beijing, which is similar to that over China. Therefore, the time series of the homogenized daily maximum and minimum temperatures over century-long scale in Beijing city can to a certain extent provide a new data source for the study of climate extremes.