Derived from the Yak-25, from which it differed primarily in having wings sweptback 35° at quarter chord, the Yak-30 retained the fuselage, tail surfaces and undercarriage of the earlier fighter.

The Yak-30 was designed to meet a Soviet requirement for a fighter capable of Mach 0.9, and able to operate from existing unpaved airstrips.

The wingtip tanks could not be used, as they moved the aircraft's center of gravity too far back, so they were redesigned to fit flush under the wing, midway from the fuselage.

The second prototype, the Yak-30D, which joined the flight test programme early in 1949, had a 38 cm (15 in) section inserted in the aft fuselage, revised mainwheel doors forming a large section of the fuselage skinning, Fowler-type flaps in place of split flaps, increased fuel and ammunition capacity, and changes to the oxygen system and radio equipment.

Although the modifications introduced by the Yak-30D eradicated several shortcomings displayed by the first prototype, the first production deliveries of the superior MiG-15 were already taking place by the time that the improved version of the Yakovlev fighter entered flight test, and the results of NII V-VS trials were, therefore, little more than academic.