摘要:From 2015 to 2019, samples of surface mud from the bottom of the artificial lake in Tianjin Normal University were collected for diatom analysis and identification in May and June. 1296 diatoms were identified and divided into 25 species. DAIpo (Diatom Assemblage Index to organic water pollution) was calculated: 56 in 2015, 76 in 2017, 58 in 2018 and 63 in 2019. In 2017, it was β-oligosaprobic, and in 2015, 2018 and 2019, it belonged to α-oligosaprobic. The Jinyaoshi Lake is an artificial lake where groundwater is exposed by artificial excavation, and its water source mainly comes from groundwater, then by precipitation. It shows that the pollution degree of the Jinyaoshi Lake was not serious since 2015, and its pollution level was α or β-oligosaprobic.