Superior colliculus-pulvinar-amygdala pathway is one of the subcortical visual pathways in mammalian brain. Some recentstudies suggest that this pathway is involved in processing emotion-related visual information. This review discusses the possibilitythat this pathway is more related to visual alert rather than simply the early visual information processing. The biological significanceof this pathway is also discussed. Instead of detecting “where” or “what” the visual target is, the task of this early visual stage is tosend out a warning signal, i.e., “something appears”, so that the brain can be set up in a state of alert, which is important for thesurvival of animals. Thus, in the early visual information process, detection of new object “emerging” or “disappearing” takes priorityover the acquisition of its feature information of “texture” and “shape”, etc. The subcortical pathway may provide the neural basis ofearly visual warning in topological perception, a biological significance critical for animal survival.