Sensing the temperature of the surrounding environment should be an important trait for organisms in terms of adaptation. Several members of transient receptor potential (TRP) superfamily are known to function as thermo sensors. These genes are called as thermoTRPs. TRPs are ion channels which have six transmembrane domains. ThermoTRPs open their channel by the heat or cold stimuli, but the number of thermoTRPs members or the temperature they sense is frequently changed during evolution. I conducted analysis to find out the candidates of TRPs in the genomes and transcriptomes of two echinoderms, sea urchin and starfish. The larvae of them have been shown to have thermotaxis and the thermoTRPs of them are supposed to play a great role. Based on HMM search using known TRPs, I found that sea urchin and starfish both potentially have almost the same number of TRP genes as vertebrates. I also found that sea urchin has more TRPA genes than fruit fly or human. The unusual expansion of TRPA genes in sea urchin may have functionally important for its thermotaxis and adaptation.