Title: AMA: Asymptotic Midpoint Augmentation for Margin Balancing and Moderate Broadening. Abstract: Margin plays an important role like alignment and uniformity for regularization, as shown in contrastive learning literature. However, feature augmentation has been rarely analyzed in this framework, despite their effective regularization. In this paper, we focus on the analysis framework for feature augmentations and propose a novel method to gradually push a decision boundary to the midpoint of related representations via their augmentation, called $\textit{asymptotic midpoint augmentation}$ (AMA). The method induces two effects: 1) balancing the margin for all classes and 2) only moderately broadening the margin until it holds maximal confidence. Each effect addresses the low uniformity of feature augmentations and representation collapse by excessively low alignment of contrastive learning, respectively. We empirically analyze the effects in a toy task for clear visualization and validate the impacts in original, long-tailed, and coarse-to-fine transfer tasks on CIFAR-10 and CIFAR-100.