Series of star-shaped three arms oligoimides (SOI) with terminal amino groups with narrow MWD ((M-w/M-n = 1.1-2) was synthesized by the one-stage high-temperature polycondensation in molten benzoic acid at 140 degrees C. The (B3+AB ') approach with the "slow addition of monomer" method was used for this synthesis, where B3 is 2,4,6-tris(4-aminophenoxy)-toluene and AB' is 3-aminophenoxy phthalic acid. The 801 arm's length was controlled by the AB'/B3 mole ratio of 10:1, 20:1, 401, and 100:1, By the reaction of SOI's terminal amino groups with acetic anhydride, corresponding acetamide derivatives were obtained. SOI synthesized are soluble in selected organic solvents. (C) 2018 Wiley Periodicals, Inc.