The easternmost point of China lies at the intersection of the middle line of Heilongjiang main channel and Wusuli River.
The northernmost position of China is on the center line of Heilongjiang main channel at the northern end of Mohe County;
The westernmost point of China is on the Pamirs;
The southernmost tip of China lies in Zengmu shoal in Nansha Islands.
Fuyuan, the easternmost city in China;
Sanya, the southernmost city in China;
Heihe City, Heilongjiang Province, the northernmost city in China;
The westernmost city in China is Wuqia, Xinjiang.
More specific answer:
The westernmost part of China is located in Wuqia County, Xinjiang on the Pamirs. The specific location is about 39 degrees north latitude 15 minutes, and 73 degrees 33 minutes east longitude. About 25 kilometers southwest of the junction of China, Tajikistan and Kyrgyzstan, there is a snow peak with an altitude of more than 5,000 meters.
The northernmost part of China is located in Shangmohe County, Heilongjiang Province, but it is not Mohe Town as people usually think, but in Wusuli Town, more than 60 kilometers east of Mohe Town, which is the northernmost latitude of the main channel of Heilongjiang Province, 53 degrees 33.5 minutes north latitude. The northernmost latitude of Mohe Town is 53 degrees 30 minutes north latitude.
The easternmost part of Russian territory used to be the intersection of the main waterways of Heilongjiang and Wusuli rivers, but since China and China reached an agreement to carve up the Black Box Island, the situation has changed.
Before the two sides complete the demarcation of Heixiazi Island, there may be two candidates for the easternmost territory of China: (1) it may be in Heixiazi Island; (2) It may also be in the center of Wusuli River (east longitude 134 degrees 46.5 minutes) more than 60 kilometers south of Heixiazi Island, and the nearest town is Haiqing Town, Fuyuan County.
Theoretically, the southernmost territory of China is Zengmu shoal (latitude 3 degrees 5 1 min, longitude12 degrees 16 min), but it is a reef beach submerged 20 meters underwater.
Nansha islands can be exposed to the water. The southernmost one (I don't know its name) is located at 7 degrees 22 minutes north latitude and 1 13 degrees 50 minutes east longitude. Unfortunately, it was seized by other countries (probably Malaysia) and an airport was built with a runway of 1.5 km.