The Raman spectra of rubidium titanyl arsenate (RTA) single crystal with different geometric arrangements were obtained and compared with those of rubidium titanyl phosphate (RTP), potassium titanyl arsenate (KTA) and potassium titanyl phosphate (KTP) single crystals. The assignments of various vibration modes were made according to the experimental results. The strong Raman scattering intensity implies that RTA crystal possesses large nonlinear optical property and the strongest scattering is from the TiO6 octahedron. From the mode splitting of AsO4 tetrahedron, we conclude that the distortion of AsO4 in RTA is larger than that of PO4 in KTP.