Cellulose fibers were chemically modified by the oxidation of cotton fiber with sodium periodate and subsequent grafting with an amino-terminated hyperbranched polymer. The effect of the influence of the oxidation conditions was evaluated by determining the aldehyde group content, tensile strength, yield loss and Fourier Transform Infrared Spectroscopy (FTIR). In the absence of salt, the oxidized hyperbranched cotton fiber (OHCF) displayed a notable improvement in colour strength compared to the untreated cotton fiber. In order to achieve a more satisfactory result, a low-salt dyeing was carried out. Overall, good fastness properties of the dyed oxidized hyperbranched cotton fibers were obtained that are comparable to the conventional dyeing. The improvement in the measurement of colour strength indicates that the chemical modification of cellulose via periodate oxidation and grafting of the amino-terminated hyperbranched polymer was successfully implemented. It is concluded that amino-terminated hyperbranched polymer can be applied in reactive dyeing on cotton for the lowsalt dyeing auxiliary to improve the substantivity of cellulose towards reactive dyes. Hence, a more environmentally friendly dyeing process was achieved.