Update publication information. Early planting is one of the strategies used to increase grain yield in temperate regions. However, poor cold tolerance in castor inhibits seed germination, resulting in lower seedling emergence and biomass. To date, proteomics studies have identified diverse proteins associated with germinating or developing castor seeds; however, the regulators involved in early imbibed castor seeds under cold stress are rare. Here, the elite castor variety Tongbi 5 was used to identify the differential abundance protein species (DAPS) between cold stress (4 °C) and control conditions (30 °C ) imbibed seeds. As a result, 127 proteins were identified to be differentially accumulated according to iTRAQ strategy. Bioinformatics analyses revealed that 84 DAPS were annotated in 24 GO functional groups, 70 DAPS were classified into 16 COG categories, and 56 DAPS were involved in 16 KEGG pathways. Based on physiological index assays and iTRAQ results, this study provided some invaluable insights into the cold stress responses of early imbibed castor seeds.