In today’s ever-intensifying competitive environment, new product development is the prerequisite for corporate survival and growth. Therefore practitioners and researchers are highly interested in factors which affect the success of new products. While buyer collaboration is identified as one of NPD success factors and the view that it positively influences NPD performance is widespread, multiple studies and cases show that it does not necessarily guarantee better NPD performance. The inconsistency arises from studying buyer collaboration only in the context of NPD success factors. From the supply chain management viewpoint, buyer collaboration is not only one of success factors for a specific NPD project, but also a decision variable that interacts with buyer-supplier relationship. Hence integrative approach of NPD and supply chain management is necessary to examine the effect of buyer collaboration on NPD success, but empirical research in the area remains underdeveloped. To reveal the moderating role of the buyer-supplier relationships in the path from buyer collaboration to NPD performance, 4 main hypotheses are derived as follows:H1: Buyer collaboration has a positive effect on NPD project performance. H2: NPD project performance has a positive effect on NPD market performance. H3: Buyer collaboration has a positive effect on NPD market performance. H4: Supplier's dependence on the buyer has a negative moderating effect H4-1: on the relationship posited in Hypotheses 1. H4-2: on the relationship posited in Hypotheses 2. H4-3: on the relationship posited in Hypotheses 3. 176 datasets are collected from Korean manufacturing firms and Structural Equation Modeling(SEM) analysis is conducted to test hypotheses regarding the impact of buyer collaboration on NPD project performance and NPD market performance, and hypotheses 1, 2and 3 are supported. Multi-group analysis followed by c2 difference test is applied to test hypotheses about the moderating role of supplier’s dependence on the buyer, and hypotheses 4-2 and 4-3 are accepted. The result shows that buyer collaboration in the NPD project has a positive impact on the NPD project performance and better NPD project performance leads to the better NPD market performance. At the same time, buyer collaboration directly affects NPD market performance. Furthermore, it is derived through multi-group analysis that supplier’s dependence on the buyer negatively moderates the path from buyer collaboration to NPD success. The study provides a significant implication that collaboration with the buyer, which is recognized as a new product success factor, is less effective in improving NPD market performance when a supplier is highly dependent on the buyer, i.e., that the NPD success interacts with buyer-supplier relationship. Although higher NPD project performance is achieved through collaboration with the buyer, this may not lead to equally high market performance in case of high dependence on the buyer. In this case, buyers may behave in opportunistic ways using their superior power, and suppliers are likely to be compromised on their profit from the new product. We suggest that success of buyer collaboration is significantly affected by the nature of buyer-supplier relationships. Therefore, careful evaluation on the established relationship with the buyer should be done before entering into collaborative relationships to get the most out of NPD success. This study is significant in that it breaks new ground in the study of NPD by examining the effect of buyer collaboration on NPD success from the perspectives of supply chain management,in particular, buyer-supplier relationships.