The role and mechanisms of sediment cohesiveness in dune formation and evolution remain incompletely understood. To quantify its impact on dune morphology and dynamics, a comparative study was conducted in China's Boketai dune-field in the northeastern Alxa Plateau, focusing on two adjacent sites: a cohesive dune field in a playa basin and a non-cohesive dune field on a Gobi surface. Field observations at both sites included analyses of wind regime, near-surface sand transport, sediment grain-size distributions, anion and calcium carbonate content, mineral composition, and dune morphological characteristics and dynamics. Significant differences were observed between the cohesive and non-cohesive dunes, which formed under an obtuse bimodal wind regime. Cohesive dunes featured finer sediments with higher anions and calcium carbonate contents, and larger sizes. These dunes exhibited greater stability with smaller temporal variations in morphological parameters and reduced migration rates. Despite differing boundary conditions and mobility, both sites adhered to the same sand transport laws. The findings indicate that the crusting effect reduces the sensitivity of dunes to variations in wind conditions and modifies their developmental processes. Sediment cohesiveness is thus a critical factor in interpreting dune morphology to infer local wind environments, especially when detailed field surveys are unavailable. This study provides valuable theoretical insights for refining dune evolution models and enhancing strategies for desertification and sandstorm management.