Otolith is a typical biomineral carrier growing on insides of fish skull with prominent zoning structure formed by alternating layers of protein and calcium carbonate growing around the nucleus. Even though thermoluminescence (TL) analysis on biomineral has been widely used to measure the radiation exposure in recent twenty years, the TL characteristics of the fish otolith have not yet been reported in the literature. TL characteristics of otoliths from the wild carps (cyprinoid) living in the Baiyangdian Lake, Hebei Province and Miyun Reservoir, Beijing City was firstly studied, as well as the differences of energy gap (E) between the fish otoliths in the two waters have also been discussed in this paper. The experimental results indicate that TL curve parameters: peak temperature (Tp), luminous intensity (I), integrated intensity (S) and middle width (Wm) for the glow curves of the cyprinoid otoliths from Baiyangdian Lake are greater than those from Miyun reservoir, and the stability of the formers’ TL curve parameters value and energy gap (E) is weaker than the latters’. In comparison to the Miyun Reservoir, the analysis manifest that the electrons and vacancies that trapped in the otoliths from Baiyangdian Lake are more likely to escape. According to the investigation, the contaminative degree and eutrophication in the water of Baiyangdian Lake is heavier than that of Miyun Reservoir. So the characteristics of TL growth curves of the cyprinoid otoliths is quite sensitive to heavier contaminated and less contaminated water, and it could be regarded as an important typomorphic biomineral for monitoring the contaminative degree and environment change of the water.