Height reduction of compressive coil springs (height loss) is considered to be the effect of creep phenomenon. Height loss of coil springs made of SWOSC-V behaves 3 different temperature dependency in elevated temperature zone, namely lower region (100-200℃), mid region (250-300℃), and higher region (350-400℃). These behavior are quite different from much elevated temperature region. In lower region, Cottrell effect seems to be the governing factor of creep speed. On the other hand, IS effect has the governing role in higher region. In mid region, the creep speed is governed by a transition mechanism from Cottrell to IS effect.