Abstract: In this study, the environmental behavior and fate of Cr in post-remediation sites in central China were studied. Three rounds of follow-up monitoring of Cr contents and forms in the soils and plants were carried out. The leaching characteristics and form transformation of Cr were explored using LEAF, BCR procedures, and micro-characterization. The results show that: (1) The total amount of Cr in the soils decreased significantly, with an average decrease of 18.92%. The content of Cr (in dry weight) in Brassica juncea leaves was as high as 1.62 mg/kg, Cr (in dry weight) in stems was 0.69-0.77 mg/kg, and Cr content in fresh Brassica juncea was 0.12-0.69 mg/kg, which exceeds the National Standard for Food Safety-Limits of Contaminants in Foods (GB 2762—2017) standard limit (0.5 mg/kg). Although the contribution of Cr removal via plant harvest was less than 0.05%, the potential health implication should be addressed in the post-remediation phase. (2) The key mechanism of Cr solidification/stabilization was the conversion of highly toxic and mobile Cr(Ⅵ) to less toxic and mobile Cr(Ⅲ). However, the co-existing Mn_xO_y could re-oxidize Cr, leading to high mobility of Cr as shown in the LEAF data. This finding was further supported by BCR analysis, which showed that the proportion of reducible Cr increased gradually from 1.13% to 4.02%. (3) Complicated environmental behaviors of Cr, such as oxidation/reduction and dissolution/precipitation in soils, as well as the migration and transformation associated with plants, were involved in the post-remediation site. The main influencing factors included pH, Mn, Fe and plants, while the Mn(Ⅳ) in soils played a crucial role, which leads to the dissolution/reoxidation of the solidified/stabilized Cr to Cr(Ⅵ) and the dissolution, thus increasing the mobility and toxicity of Cr and posing environmental risks. This study reveals that the environmental behavior of Cr in the post-remediation sites is affected by a variety of environmental factors, especially in the area with high Mn content, which is prone to the formation of oxidation atmosphere, leading to the reactivation of Cr.