Lake eutrophication is concerning because of its harmful effects on water ecosystems. The field sam- plings were collected to investigate various forms of phosphorus in the water columns, clarifying the rela- tionship between phosphorus levels and types of primary producers (cyanobacteria and macrophytes) in the different regions of Lake Taihu in China. High phosphorus levels were observed in Meiliang Bay suffering from cyanobacterial bloom, while phosphorus concentrations were relative lower in Xukou Bay and East Lake Taihu, where many macrophytes grow. Thus, cyanobacteria and macrophytes could significantly affect phos- phorus forms and contents in the different lake regions. In Meiliang Bay, aqueous total phosphorus (TP_aquesous) concentrations (0.312±0.158 mg·L^-1), total dissolved phosphorus concentrations (0.108±0.072 mg·L^-1), and dissolved inorganic phosphorus concentrations (0.018±0.022 mg·L^-1) were much higher in July under the action of cyanobacteria than in any other period. Aqueous phosphorus concentrations in Xukou Bay and East Lake Taihu were much lower in July due to macrophyte growth. However, macrophyte decomposition made TP_aquesous concentrations in Xukou Bay extremely high in December. Furthermore, Exchangeable phosphorus (Ex-P), Al-combined phosphorus (Al-P), Fe-combined phosphorus (Fe-P), Autogenetic calcium phosphorus (ACa-P), detritus calcium phosphorus (De-P), and organic phosphorus (Or-P) in Meiliang Bay were much lower in July due to the action of cyanobacteria. However, only Ex-P, ACa-P, and Or-P contents in the sedi- ments of macrophyte-dominated lake regions were much lower in July due to the growth of macrophytes. Therefore, interactions between phosphorus contents and types of primary producers were simultaneously observed in a single lake.