The water pollution emission inventory is a fundamental decision-making tool that links emissions and water quality. However, accurately quantifying the emissions is challenging, due to the variety of contributing sources, complexity of methods for calibration and validation, and lack of moderate spatio-temporal resolution. Over the last two decades, tremendous efforts have been made to improve the accuracy of emission inventories, and significant improvements have been accomplished. This study summarizes the recent progress on inventory development, by recapping the sector-based configurations and associated coefficient databases. Subsequently, we highlight the calculation, validation, and spatio-temporal resolution of emissions contained in the present inventories. Finally, we suggest future directions for conducting a systematic procedure and further improving the accuracy of emission inventories.