This study primarily examined the thermal aggregation behaviour of bevacizumab biosimilars in comparison totheinnovator. It focused on the variations in their N-glycan compositions. The percentages of aggregate variations werequantified using size exclusion chromatography. The study successfully measured and quantified the N-glycans of four bevacizumab biosimilars (AVZ, BRX, BVZ, and IVZ) and the innovator (AST) using LC-MS/Q-TOF. It wasidentified that all bevacizumab biosimilars contained different quantities of N-glycan compositions compared totheinnovator. Compared to all biosimilars, innovators have a higher percentage of fucosylated N-glycans (86.50%), while Bryxta (BRX) has a lower percentage (65.40%). This study revealed variations in glycan composition, emphasising that fucose-related glycans play a substantial role in the stability and formation of aggregates inmonoclonal antibodies. Research showed that higher levels of fucose-related glycans are linked to a lower percentage of aggregates observed during thermal aggregation studies. Conversely, lower levels of these glycansresult in a higher percentage of aggregates.