Riverine carbon concentration play important role in the global carbon cycle. Carbon concentrations are affected by many factors such as lithological – geological characteristics, meteorological and hydrological characteristics and human activities. This paper presented the observation results of carbon concentrations including particulate and dissolved organic carbon (POC and DOC) and inorganic carbon (DIC) in the four urban rivers in Hanoi during sampling campaigns from February and April in 2020. Ther results showed that POC concentrations at 8 observed sites of the four rivers ranged from 1.8 to 4.9 mgC/l, averaging 3.6± 0.9 mgC/l and DOC varied from 7.3 – 19.0 mgC/l, averaging 11.5± 2.4 mg/l whereas DIC concentrations fluctuated from 47.0 to 94.4 mgC/l, averaging 73.2± 12 mgC/l. The significant-high concentrations of carbon in the urban rivers in Hanoi in comparison with the ones of other larger rivers reflected an important impact of human activities. Long term observation should be carried out for determining the change of carbon concentrations and fluxes of the urban rivers.