Cross-border E-commerce has grown exponentially in the past decade. To gain global competitivity in product-convergent markets, China's over 200 thousands cross-border E-commerce businesses have focused more on the service and cost of supply chain downstream. Therefore, selecting appropriate cost control strategy has marked impact on them. In this study, we evaluated three strategic cost control measures according to 10 evaluation criteria by using a complex fuzzy set based model, named C-COPRAS. The C-COPRAS model is an extension of the COmplex PRoportion ASessment (COPRAS) method. This model uses complex fuzzy set to tackle uncertainty and temporal features in given evaluation context. We then apply this model to a case study of helping a Chinese E-commerce business to select strategic cost control measure on supply chain downstream.