测量了ＲｂＴｉＯＡｓＯ４（ＲＴＡ）晶体的电光系数、介电常数和交流电导率，结果为：电光系数γ１３＝１０．８，γ２３＝１７．３，γ３３＝４０．０，γ５１＝１２．３，γ４２＝１４．６ｐｍ／Ｖ；介电常数ε１１＝ε２２＝１２，ε３３＝２１；交流电导率σｃ＝３．６×１０－８ｓ／ｃｍ。结果表明ＲＴＡ晶体波导调制器的品质因子ｎ７γ２／ε比ＫＴＰ晶体高１５％，但是其交流电导率比ＫＴＰ晶体小了两个数量级。这些性能使ＲＴＡ晶体有希望应用于波导调制器和其它电光器件。 The electro-optic coefficient, dielectric constant and AC conductivity of RbTiOAsO4 (RTA) crystals were measured. The results showed that the electro-optical coefficients γ13 = 10.8, γ23 = 17.3, γ33  = 40.0, γ51 = 12.3, γ42 = 14.6pm / V, dielectric constant ε11 = ε22 = 12, ε33 = 21; AC conductivity σc = 3.6 × 10-8s / cm. The results show that the quality factor n7γ2 / ε of RTA crystal waveguide modulator is 15% higher than that of KTP crystal, but its AC conductivity is two orders of magnitude smaller than that of KTP crystal. These properties make RTA crystals promising for waveguide modulators and other electro-optic devices.