Smart retailing has become increasingly critical in modern retailing industry. This study aims to assess the competitiveness of five leading smart retailing firms, i.e. Alibaba, Amazon, eBay, Google and Microsoft by analyzing their technological capability and technological knowledge flows. To obtain the objective of this study, technological knowledge of these five firms were characterized and knowledge interdependence network was created. It is found that Microsoft could serve as the most significant knowledge source that are both novel and fundamental in the smart retailing innovation ecosystem underpinned by the five leading firms. In this innovation ecosystem, the ranking of knowledge influence from these companies is: (1) Microsoft, (2) Google, (3) Amazon, (4) eBay and (5) Alibaba.