The study looked at the pollution levels in rainwater flowing through Beijing streets and roofs. The research found that the runoff from streets in Beijing can directly pollute waterbodies. Street water had higher levels of some pollutants like TN, TP, COD, and BOD compared to roof water. Around 83.1% of TP in street water was linked to particles. Filtration or settling could help reduce pollutant levels in all types of runoff. Pollutant concentrations in runoff decreased over time during rain, with early runoff being the most polluted. Overall, the study shows that urban runoff in Beijing carries harmful pollutants that need attention.