Dekoruma is an Indonesia-based home and living e-Commerce with an urgency to improve the quality of service and shopping experience for its customers. This study is conducted to evaluate usability aspects of Dekoruma's current e-Commerce site and propose an alternative design to improve the usability. The methods used for data collection and analysis in this study are the mixed method approach, and the alternative design development is conducted using the User-Centered Design (UCD) approach. The quantitative data are collected through online questionnaires addressing users' demographic data and behavior in using Dekoruma website and System Usability Scale. Usability testing is conducted to collect qualitative data directly from end-users. Identified usability problems are mapped to relate interface design principles. Proposed solutions are built into a high fidelity prototype as the end result. The usability testing of the alternative design shows that most of the proposed solutions are able to solve usability problems encountered beforehand. Further improvement is still needed on product filter and product detail features.