Abstract
This review focused on aquatic humic substances in groundwater. Humic substances are large molecular，heterogeneous mixtures of many organic compounds and comprise a major fraction of dissolved organic materials in natural waters. Humic substances may play an important role related to the migration behavior of TRU nuclides in underground layer because of the high complexation affinity to TRU nuclides. This report summarized characteristics (elemental composition，functional groups，molecular weight，etc.) of humic substances in groundwater and stability constants for TRU nuclides-groundwater humates.
