Mikoyan-Gurevich MiG-15, Chinese and Korean users

The MiG-15 was widely exported, with the People's Republic of China (PRC) receiving in 1950 an amount of Mikoyan-MiG-15. In fact, it saw action first during the closing stages of the late period of the Chinese civil war, at the opening months of 1950.
During the early part of 1950, the Chinese Nationalist Air Force was attacking Chinese Communist positions in mainland China from their bases in Taiwan, concentrating their efforts specially on the Shanghai region.
That's why Mao Zedong requested military aid from the USSR, and therefore the 50th IAD (Fighter Regiment) which was equipped with the earlier version of the MiG-15 was deployed in the southern region of mainland China. Shortly later the first aerial victory was achieved when a MiG-15 shot down a Nationalist P-38 Lightning on 28th April 1950 and shortly later, on 11th May, Cpt. Ilya I. Schinkarenko shot down the B-24 Liberator commanded by Li Chao Hua, who was the commander of the Nationalist 8th Air Group.
Later, from late June 1950 the first jet-against-jet dogfights took place in the Korean war where the MiG-15 with its swept wing proved superior to the first generation of the western powers which had straight-wings, like the F-80 Shooting Star or the Gloster Meteor. They also proved to be superior to the piston-powered fighters like the P-51 or the F-4 Corsair. The first jet-to-jet dogfight in history was won by First Lieutenant Semyon F. Fyodorovich Khominich when he shot down the F-80C of Frank Sickle who died in the dogfight, although the official USAF credits the loss to North Korean flak.
When the People's Republic of China entered the Korean war, after having formed the People's Volunteer Army, whose Air Corps was equipped with the MiG-15 which showed as a very unpleasant surprise for the United Nations pilots and against the F-80 and Gloster Meteors. Only until the F-86 came in, the MiG-15 had a worthy contender.
Some Soviet units flew the MiG-15 in North Korean colours (whose Air Force, equipped with a mixture of vintage World War II Soviet and captured Japanese aircraft like the Yakovlev Yak-9P was almost destroyed on the ground). The 324th IAD, which was comprised of two regiments, the 176th GIAP and 196th IAP were rebased to airfield along the Yalu river in late 1950 where they engaged many UN forces.

Sources:
1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-15
2. https://en.wikipedia.org/wiki/People%27s_Volunteer_Army
3. Salamander Books - The Complete Book of Fighters