The Polikarpov I-170 was a design for version of the I-153 biplane fighter with a wooden fuselage structure in place of the metal tubing used on the standard aircraft. Polikarpov had previously made a stand against all-metal aircraft, and the I-170 was a continuation of that attitude. The new also featured tapered wings in place of the straight sided wings of the I-153, and would have been powered by the M-106 liquid cooled engine.
Design work began in the summer of 1939. Polikarpov expected the basic design to be completed by mid-October and a mock-up by mid-November, but he then fell foul of Soviet politics. In October 1939 he paid a visit to Germany, and in his absence a large part of his design team was taken away to form part of the new Mikoyan team. Although Polikarpov continued with his design work for some time after this, the I-170 was one of the projects that was abandoned.