The fast growing cross-border e-commerce makes it imperative for online merchants to deeply understand the cross-national differences in consumers’ preferences and online shopping behaviors. Using a data-driven topic model, this study plans to investigate the semantic differences in online product reviews posted by consumers from China and the United Sates. The preliminary results from a pilot study of online reviews of books show that Chinese reviewers focus more on a product’s concrete attributes while American reviewers prefer to express their general evaluations of the product.