By air — Kashgar Airport (KHG) receives flights from Urumqi, Beijing, Xi'an, and several other Chinese cities. China Southern, Xinjiang Airlines, and several other carriers serve the route. The flight from Urumqi takes about two hours and is often the most practical option given the distances involved. The airport is about ten kilometres north of the city centre.
By train — Kashgar is connected to Urumqi by the Southern Xinjiang Railway, a journey of roughly 24 hours by overnight train. This is a genuine option if you want to see the landscape — the line passes through the northern edge of the Taklamakan Desert and crosses some striking terrain — but it is a long haul. Trains are comfortable by Chinese standards and bookable through the national rail system (12306.cn) or via agents in Urumqi.
Overland from Pakistan — The Karakoram Highway crossing at the Khunjerab Pass connects Kashgar to Gilgit and Islamabad. The crossing is open from approximately May to October (weather-dependent). You can travel by public bus or arrange a private vehicle. Allow two days from Gilgit to Kashgar. A valid Chinese visa is required and must be obtained before arrival.
Overland from Kyrgyzstan — The Torugart Pass (3,752 metres) connects Kashgar to Naryn and Bishkek. This is a more restricted crossing requiring advance arrangement: you need a special permit from the Chinese side and transport arranged on both sides of the border. It is manageable but requires more planning than the Khunjerab crossing.