Droplet breakup in an asymmetric bifurcation with two angled branches is studied experimentally and theoretically in this paper. In order to tune the droplet size and droplet velocity separately, a diluting channel is added and its influence on droplet generation is confirmed to be negligible. The underlying physics of the droplet generation is revealed as compared with other works. Effects of the droplet parameters, including the initial droplet length and the droplet velocity, on breakup characteristics are analyzed. The regime diagram of the droplet breakup and the critical conditions between different regimes are provided. It is found that the splitting ratio is largely influenced by the initial droplet length and the droplet velocity, which indicates that the breakup process is an inter-dependent process between the splitting junction and droplets themselves. At last, a simple but effective prediction model is constructed by considering the hydrodynamic resistance of the branches with the presence of the daughter droplets, which also proves the similar motion of the droplets with low viscosity ratio of the two liquids and the bubble. (C) 2018 Elsevier Ltd. All rights reserved.