Lithium-ion batteries (LIBs) have been widely used in portable electronic devices and electric vehicles. However, with the exploitation of lithium resources in the earth's crust, the cost of LIBs is gradually increasing. In contrast, the higher potassium content in the earth's crust promises the low cost of potassium ion battery (KIB). Thus, KIBs have attracted lots of attentions. However, the potassium ion with large radius leads to unsatisfied ion (de)intercalation behavior during charging and discharging processes. It is still a challenge to explore capable electrode materials for KIBs. This review summarizes the anode and cathode materials for KIBs, including the research progress of graphite and other carbon materials, transition metal oxides, alloys and other anode materials, as well as Prussian blue, layered metal oxides, and polyanionic compound cathode materials. In addition, we point out the key factors for KIBs performance, which would provide new thought for the development of high-performance potassium ion battery.