Travel to Vietnam

Go to vietnam by plane
Vietnam has international airports at Hanoi, Ho Chi Minh City, and Da Nang. Direct flights are available from Australia, Cambodia, China, France, Germany, Hong Kong, Japan, Laos, Malaysia, New Zealand, Philippines, Russia, Singapore, Brunei, South Korea, Thailand, Taiwan, Indonesia, Macau, Qatar and the United States. However, non-stop long-distance flights are limited and most visitors transit via Bangkok, Hong Kong, Singapore and Taipei.
Go to vietnam by train
There are direct international train services from Nanning and Beijing in China to Hanoi. Most require a change of trains at the border at Pingxiang/Dong Dang, but the Chinese-operated daily Nanning express (T871/MR2) runs through, although it still spends about four hours at the border for immigration.
The Kunming-Hanoi line was shut down by landslides in 2002 and, as of 2009, remains closed. There are no train links to Cambodia.
Go to vietnam by road
1- From Cambodia:
There are at least four border crossings between Cambodia and Vietnam that can be used by foreigners. These include:
Bavet - Moc Bai
Kaam Samnor - Vinh Xuong (in some guidebooks as Tonle Mekong. Near Chau Doc in Vietnam)
Phnom Den - Tinh Bien
Xa Xia, Vietnam/Prek Chak, Cambodia (Ha Tien crossing, Cambodian Visas not available)
The Vietnamese consulate in Sihanoukville issues 30 day tourist visas on a same-day basis.
2- From China:
There are three border crossings between China and Vietnam that can be used by foreigners:
Dongxing - Mong Cai (by road; onward travel Mong Cai to Halong by sea or by road)
Hekou - Lao Cai (by road and/or rail, but no international passenger train services)
Youyi Guan - Huu Nghi Quan (Friendship Pass - by road and/or rail)
3- From Laos:
There are at least six border crossings between Laos and Vietnam that can be used by foreigners. These include:
Donsavanh - Lao Bao
Kaew Neua - Cau Treo (Keo Nua Pass)
Nam Can
Tay Trang

Source: wikitravel