In this paper, we research on fin thickness (Tfin) and fin height (Hfin) effects on read stability and write ability of tri-gate FinFET based SRAM cell. The degree of drain induced barrier lowering changes with Tfin and fin Hfin. This makes threshold voltage (Vth) vary. Thus, Tfin and Hfin also influence the mean and standard deviation of read static noise margin (RSNM) and word-line write trip voltage (WWTV) since Vth variation is a dominant factor determining them. If Tfin increases, the mean of RSNM (μRSNM) and the mean of WWTV (μWWTV) decreases and increases, respectively, while the standard deviation of RSNM (σRSNM) and WWTV (σWWTV) are almost not changed. If Hfin increases, the μRSNM and μWWTV decreases and increases, respectively, while both σRSNM and σWWTV decrease. However, for a sufficiently small Tfin, the effect of Hfin on μRSNM and μWWTV becomes negligible.