Red soil (earth) is a folk term meaning soils with red color. Red soil is a vital issue in Quaternary research. This work reviews recent research of the red soil in Taiwan, emphasizing the classifications, origins and evolution of the red soil. The study suggests that researchers in Taiwan employ several classification systems based on the purposes of the research. However, no correlation between those classification systems has been proposed yet. Second, the provenances of the red soils were ploygenic, intead of monogenic; this is attributed to geomorphic processes, climatic fluctuation and environmental changes. Furthermore, hypotheses about evolutionary processes and developmental time of the red soils are still controversial. Additional dating information and contructed chronosequences for the red soils are necessary.