There is highly risk of odorous compounds trouble in drinking water source reservoirs in the Changjiang River catchment in later spring. However, the key drivers for the odorous compound occurrence are remain unclear. During May 2024, we investigated nine drinking water source reservoirs across the upper, middle and lower reaches of the Changjiang River, measuring four odorous compounds, included 2-methylisoborneol (2-MIB), geosmin (GSM), β-cyclocitral (CYC) and β-ionone (ION), along with associated environmental factors. Results showed that 2-MIB was the most common odorous compound, with an average concentration of 35.5 ng/L across the 32 samples from 9 reservoirs (59.4 % exceeding the detection threshold of 10.0 ng/L). In contrast, GSM posed a lower risk, with an average concentration of 2.9 ng/L and only 12.5 % exceeding the threshold value of 10 ng/L, while CYC (averaged at 18.2 ng/L) and ION (averaged at 7.2 ng/L) exhibited minimal odorous concerns. Pseudanabaena sp. was identified as a likely major producer of 2-MIB, with its cell density showing a significant positive correlation with the concentration of 2-MIB. However, the presence of 2-MIB in two reservoirs without detectable Pseudanabaena suggests more complex 2-MIB sources in some reservoirs. Furthermore, 2-MIB levels were also positively related to the trophic state index (TSI), indicating that eutrophication could promoted 2-MIB production. Rainfall amount in 7 days ahead the sampling (RF7) was negative relative to 2-MIB concentration, suggested that short-term weather condition also influence the odorous situation in reservoirs. Despite generally mesotrophic conditions, the widespread 2-MIB exceedances highlight a persistent risk in these reservoirs. To ensure drinking water quality, measures such as reducing external nutrient loads and optimizing aquatic food webs are recommended.