Abstract: As an important resource for human survival and development, water resources play an important role in maintaining the health and stability of ecosystems and sustainable social and economic development． With continued progress and development of remote sensing technology, it is of great significance to carry out dynamic monitoring and analysis of water bodies through remote sensing for scientific management and sustainable development of water resources． Interferences from clouds, cloud shadows, and other factors often make it difficult to obtain water area data with high temporal resolution． Long-term high-resolution water mask dataset is examined in this work, water classification enhancement algorithm was applied to correct pixels polluted by clouds, cloud shadows, terrain shadows, to provide a monthly water cover map and water area data of the Taihu Lake from 1985-2020． The average water area was found to be 2421.00 km², the data variance was sharply reduced compared with before correction． The averaged area enhancement rate was reliably only 20.76%． These data could be used to support water analysis and management, to provide support for maintaining ecological balance and sustainable use of water resources in this region．