There is a developed highway system in Guangzhou. Guang-Fo(Guangzhou-Foshan) Highway and Guang-Hua Highway were put into use in succession. Now, there are more than ten coach stations in Guangzhou offering plenty of coaches to different cities and counties in and out of Guangdong Province.
Guangzhou Provincial Bus Station is the largest bus station in Guangdong province. Buses depart here daily to the neighboring Guangxi, Hunan, Fujian and Jiangxi Provinces. There are also deluxe buses to Shenzhen, Hong Kong and Macau. The easiest way from Guangzhou to Hong Kong is by the deluxe bus following along the Guangzhou-Shenzhen freeway in 2.5 hours.
Note: the bus station is really in chaos and extremely crowded during peak travel season and tranditional Chinese holidays. Avoid it and try flight as long as possible.