Heavy metals have negative effect on human life and the environment. Therefore, evaluation of the concentration of concentration and origin of Heavy mertals can leads to take necessary management action to improve the human’s life and environmental condition. In various aquatic environments such as Wetlands, sediments can act as sink for Heavy metals. The Heavy metals in the sediments can be release into the water column through various physical and chemical processes and make a lot of problems for organism of aquatic ecosystem. The purpose of this study was to determine the concentration of heavy metals (Cd, Pb, Zn, Ni) in core sediments of International Gavkhooni wetland’s delta and finally determine the Flux and origin of these metals that accumulated in sediments of last two centuries of wetland’s delta. In this research, two sedimentary cores with length of 74 cm and 40 cm were collected From Shakh kenar and Kooh siah station, respectively and physicochemically parameters (% Moisture, Bulk and Dry density, Particle size, Organic matter, Calcium Carbonate, pH, EC) performed on 40 samples. In order to determine the total concentration of Heavy metals (Cd, Pb, Zn, Ni), Samples were digested with Aqua regia (3 unit ofNitric acid and 1 unit of Chloride acid) and the resulting solutions were analyzed by AAS (Flame). Modify BCR method was used to extract metals from various geo chemical section and determine the origin of studied heavy metals in 10 selected samples from Kooh siah sedimentary core. Also, the average total concentration of Heavy metals compared with the ERL, ERM, TEL and PEL and Enrichment Factor and Geoaccumulation Index were used to study the degree of environmetal contamination by heavy metals. The result showed that the range of Cd, Pb, Zn, Ni in core sediment of Shakh kenar station was (0.35-5.6), (1.1-5.15), (22.6-56.45) and (13.7-47.75) µg.g -1 , Respectively and in core sediments of Kooh siah (0.7-4.4), (3.1-7.8), (28.2-63.65) and (20.75-48.45) µg.g -1 , Respectively. Cd and Ni in both sedimentary cores of Shakh kenar and Kooh siah was higher than ERL and TEL and less than ERM and PEL. In contrast, the mean concentration of Pb and Zn are less than ERL, ERM, TEL and PEL in two sedimentary cores of Shakh kenar and Kooh siah station and indicating that this areas are not contaminated by these heavy metals. The result of correlation analysis and extraction of Heavy metals on 10 selected layers of sedimentary core of Kooh siah station indicate the same and natural source for Zn and Ni. On the other hand, due to the higher Extraction of Cd and Pb in first and second stages of sequential extraction in compared with Zn and Ni and as well as the result of enrichment factor, it can be concluded that the natural origin for these two Heavy metals is not dominant and anthropogenic sources can be affective. Comparison of the trend of heavy metal pollution Flux and SPI and SDI trends in Gavkhooni basin, shows the direct effect of wet Period on increase of Heavy metals pollution flux in sediments of gavkhooni wetland delta KEYWORDS: Gavkhooni wetland, Dating, Core sediment, Heavy metals, Modified BCR