Protein aggregation is a common phenomenon in nature and often occurs during protein manufacturing processes, formulation and storage. For biopharmaceutical manufacturers, protein aggregation poses a key challenge in the development and storage of biologics as it has a great impact on drug efficacy and immunogenicity. Technology to monitor and detect protein aggregation is therefore very important to ensure the quality of protein-based pharmaceuticals. Here, we described a reliable SEC method to achieve this goal quantitatively.