Some thermomagnetic curves (Js-T curves) are shown for the taken from the western half of Yamaguchi Prefecture, west Japan. Thermomagnetic (Js-T) analysis is usually performed in order to identify magnetic minerals which are responsible to the natural remanent magnetization of rocks. In this report, some Js-T curves obtained by the thermomagnetic analysis are shown for several Mesozoic/Paleozoic rocks spampled within the western half of Yamaguchi Prefecture, west Japan for the paleomagnetic study.