Abstract: The Indian Ocean deep water, as an important part of the global ocean circulation, is composed of mainly the Antarctic Bottom Water (AABW) and North Atlantic Deep Water (NADW), which is currently a research hot topic of marine substance circulation and environmental changes. We discussed the deep water redox state and composition of the bottom water through the analyses of Nd isotopes, redox-sensitive elements, total organic carbon of surface sediments in the northwestern Indian Ocean. Results show that sensitive elements such as Mn, Mo, and Ni indicated that the study area was generally in an oxidizing environment, and there was a strongly oxidizing area in the south side of the ridge. The εNd ranged from −7.16 to −8, indicating that the bottom water were mainly composed of AABW, and almost no NADW. Due to a certain amount of dust input, the study area has heavier εNd records compared with adjacent areas. The heavier εNd is indicative of an increased AABW contribution in the south, which may be influenced by the strong equatorial eastward flow within the Somali Basin. We revealed the characteristics of redox-sensitive elements and Nd isotopes of surface sediment and their possible influencing factors, and especially provided an important reference for subsequent in-depth research on bottom water.