Effect of V and Sb content on characteristics of ${eta};to;{alpha}$ phase transformation in Zr-0.84Sn alloy has been studied using optical microscopy and transmission electron microscopy. As V content increased, the ${eta}{ o}{eta}+{alpha}$ transformation temperature was lowered, thus allowing the width of $alpha$-lath in air-cooled Zr-0.86Sn-0.40V alloy to be fine. The width of ${alpha}$-lath in air-cooled Zr-0.84Sn-xSb, however, was rarely changed with Sb content. The ${eta};to;{alpha}$ transformed microstructures of water-quenched Zr-0.84Sn, Zr-0.84Sn-0.10V and Zr-0.84Sn-0.19V alloys were mainly slipped martensite. On the other hand, those of wafter-quenched Zr-0.86Sn-0.40V and Zr-0.85Sn-0.05Sb alloys were predominantly twinned martensite. In case of water-quenched Zr-0.85Sn-0.12Sb and Zr-0.84Sn-0.17Sb alloys, basketweave structure was observed. The transition of slipped martensite to twinned martensite in Zr-0.84Sn-xV alloys and the transition of twinned martensite to basketweave structure in Zr-0.84Sn-xSb alloys were due to the decrease of $M_s$ temperature.