Abstract: Seawater is considered to be a major source of uranium with an estimated quantity of around 4.5 billion metric tons, which is nearly 1 000 times higher than that available in terrestrial ores. To satisfy the needs of Chinese nuclear power industry development, extracting uranium from seawater is particularly important. Amidoxime groups can extract uranyl ions efficiently with a strong complexation ability and high selectivity. Therefore, the preparation of adsorbents is the key to the extraction uranium from seawater. In this study, we developed effective adsorbent fibers for the recovery of uranium from seawater via electron transfer activated regeneration atom-transfer radical polymerization (ARGET ATRP) from a polyvinyl chloride (PVC) fiber, and we got the different degree of grafting adsorbent by controlling the amount of acrylonitrile. Fourier Transform Infrared Spectroscopy indicated the grafted nitrile groups were converted to amidoxime groups by treating with hydroxylamine. Scanning electron microscopy was used to observe the surface morphologies of different degree of grafting adsorbent. The results showed that the optimum pH value of amidoxime adsorbents for the adsorption of uranyl ion was 5~6. With the increase of the degree of grafting of the adsorbent, the adsorption capacity and the adsorption rate were both increased, and the adsorption capacity of the adsorbent with the degree of grafting of 5 811% reached 111 mg/g. However, with the increase of the degree of grafting of the adsorbent, the gelling generated on the surface of the adsorbent hinders the adsorbent from adsorbing uranyl ions.