Hurricane Harvey, as a category four, directly passed Aransas and Copano Bays in August 25, 2017 with wind over 130 mph, which caused tremendous resuspension and sediment redistribution within the bays. The impact of this hurricane on sedimentary geochemistry is important for evaluating the ecosystem. Using surface sediments (top 5 cm) collected before (June) and (October) after the hurricane, a series of geochemical parameters, including grain size, CHN contents, polycyclic aromatic hydrocarbons (PAHs), total hydrolyzable amino acids (THAA) and n-alkanes, were measured. The sediment grain size overall became much coarser after hurricane with certain stations increasing over 100 microns in median size. Together with the OC content, concentrations of PAHs decreased from the range of 59 to 1605 ng g-1 to 19 to 204 ng g-1, and 80-100% of the decrease were attributed to the loss of low molecular weight PAHs (2-3 rings). Similarly, concentrations of n-alkanes decreased from 1.3-19.9 to 1.1-9.3 μg g-1 after the hurricane. However, there was no obvious trend among the different n-alkanes, unlike PAHs.   Among the 19 stations, the coefficients of variation of PAHs and alkanes became smaller after the hurricane, indicating that organic composition of surface sediments were more homogeneous after the hurricane. Overall, PAHs and n-alkanes are strongly correlated with grain sizes (such as clay, sand) in sediment, and these results suggest that the storm surge strongly resuspended fine sediment particles that were concentrated in PAH and alkane, leading to the loss of these fine sediment particles and associated organic matter, either suspended in the water column or exported to coastal ocean. While some analyses such as THAA are still on going, the preliminary data demonstrate the strong impact of Hurricane Harvey on sediment organic geochemistry of the Copano and Aransas Bays.