We present a theoretical scheme for conversion from ultracold atoms to heteronuclear tetrameric molecule A3B via Efimov resonace-assisted stimulated Raman adiabatic passage (ER-STIRAP). The dark state solutions of the system are obtianed for two different pathways. For the first pathway, the intermediate state is populated by homonuclear Efimov trimer A3, and the second one by heteronuclear Efimov trimer A2B. The feasibility and the effectiveness of the scheme are also verified. Meanwhile, we investigate the effects of external field parameters, including the intensity of associated laser pulses, its width, magnetic coupling strength and its detuning, on the fomation of heteronuclear tetrameric molecules. By comparison, it is found that the ultimate yield of the tetrameric molecules for the second pathway is less than ones for the first pathway. In addition, the effects of the intrinsic nolinearity of the system and the spontaneous decay in the intermediate state on the tetramer formation are discussed.