Title: Deep Relational Factorization Machines. Abstract: Factorization Machines (FMs) is an important supervised learning approach due to its unique ability to capture feature interactions when dealing with high-dimensional sparse data. However, FMs assume each sample is independently observed and hence incapable of exploiting the interactions among samples. On the contrary, Graph Neural Networks (GNNs) has become increasingly popular due to its strength at capturing the dependencies among samples. But unfortunately, it cannot efficiently handle high-dimensional sparse data, which is quite common in modern machine learning tasks.  In this work, to leverage their complementary advantages and yet overcome their issues,  we proposed a novel approach, namely Deep Relational Factorization Machines,  which can capture both the feature interaction and the sample interaction. In particular, we disclosed the relationship between the feature interaction and the graph, which opens a brand new avenue to deal with high-dimensional features. Finally, we demonstrate the effectiveness of the proposed approach with experiments on several real-world datasets.