The dynamics and interfacial evolution for bubble breakup in shear-thinning non-Newtonian fluids in microfluidic T-junction were investigated. The bubble breakup process includes three stages: squeezing, transition and rapid pinch-off stages. The minimum widths of the bubble neck in three stages exhibit a power-law relationship with the time or remaining time. Compared to bubble breakup in Newtonian fluid, the squeezing stage shortens in non-Newtonian fluid, and the power-law exponent of the rapid pinch-off stage increases with the decrease of the flow index of the CMC solutions. The length of the bubble tip is linearly stretched with time, and the elongation rate increases with the concentration of CMC solution. The results show that the rheological property of the CMC solution could significantly affect the bubble breakup process in the microfluidic T-junction. (C) 2019 Elsevier Ltd. All rights reserved.