Abstract: Alzheimer’s disease (AD), a neurodegenerative disease, is the major cause of dementia. The pathological hallmarks of AD include senile plaques aggregated by amyloid-β (Aβ), neurofibrillary tangles formed by hyperphosphorylated tau, neuron dysfunction and degeneration, and chronic inflammation in the brain. Based on these pathologies in the AD brain, there are four pathogenic hypotheses for AD. Correspondingly, drug discoveries have also been focused on the signaling pathways related to the hypotheses. This mini review summarized the progress of drug discoveries and clinical trials of AD, highlighted the recent breakthroughs in the past 5 years, and discussed the limitations in the field.