High seismicity with spatial heterogeneity in Taiwan makes this region one of the best natural laboratories for seismological researches. Numerous seismicity studies, including the b-value, have been performed for more than one century. One of the possible ways to mitigate seismic risk is predicting an impending earthquake through various kinds of seismic precursors observations. The first seismic precursors project in Taiwan started in 1978. The temporal variation in b-value prior to a forthcoming earthquake has been considered a significant seismic precursor for earthquake prediction. In this review study, we focus on the studies of b-values of earthquakes in Taiwan, including the spatial distribution of b-values, temporal variation in b-values, correlation between the b-value and fractal dimension, and correlation between the band p-value of Omori law for aftershocks. Also included is the relation between the spatial distribution of b-values and regional geotectonics. The properties and controlling factors of b-value and earthquake monitoring in Taiwan will also be briefly described.