As the secund part of a series of studies on the synthesis of 2-phenoxyisobutyric acid ethyl ester (ROPh) by tri-liquid-phase catalysis, this work examines the factors affecting the re action between 2-bromoisobutyric acid ethyl ester (RBr. organic substrate) and sodium phenolate (NaOPh, aqueous nucleophile) with tetra-n-butylammonium bromide (QBr) as a phase-transfer catalyst. The reaction is performed in a batch reactor at 40 similar to 80 degreesC for 150 minutes while the agitation speed is fixed at 1000 rpm. Experimental results indicate that the total amount of NaOPh and QBr only slightly affects the reaction, while the individual mole fractions of these components exert significant influence. When the mole fraction of QBr is 0.3, both the conversion of RBr and the fractional yield of the desired product (ROPh) are maximal. The addition of a small amount of Na2CO3 will result in a higher conversion and fractional yield. Furthermore, a high reaction temperature enhances the conversion and the fractional yield; as long as the temperature is not so high as to cause thermal decomposition of the catalyst and vaporization of the organic solvent. The optimal temperature is about 70 degreesC. Although the fractional yield by tri-liquid-phase catalysis is slightly lower than that observed with the same amount of catalyst in con ventional liquid-liquid phase-transfer catalysis, the reaction rate is higher and the catalyst can be easily re-used in the former case.