中美之间的出关入关手续，The Custom Procedures For Visitors Between China and USA
由国外返回北京，进关时大致情况是这样的：
（所有情况根据2011年初乘坐国航从旧金山返回北京的路线为参考）
1. 下飞机后，当刚走出候机大楼与飞机的连接管道后，向右转，然后上自动扶梯。
2. 下扶梯后，一直走，直到看见健康检疫站在你的右手边。马上沿着走道做个180度的转弯然后就向着入境关口走去。
3. 准备好护照和航班的登记牌（这个时候你在大楼的第三层）
4. 通过海关后，超扶梯走去，然后下降到第二层
5. 乘坐地铁前往T3-C站台
6. 下地铁后直接朝行李提取出走去。如果你的目的地就是北京，那么在提取行李后就从这里外大厅外走
7. 如果你的目的地是其它城市，那么在提供行李后，（以刚才过来的方向为准），向左转，走几步再左转就走到国内航班的区域了
8. 乘坐电梯到3楼然后前往安检处
9. 过来安检就往你的国内航班候机厅去了
这段内容也写个English版的：
If it is your first time travel from US to China, this section should be very helpful and guide you all the way from departure to destination. Note: I used the route from SFO to Beijing as an example.
1. At SFO check-in counter, you need to present valid passport, plus valid China visa if you are not Chinese citizen
2. After boarding on the aircraft, there is ~11 hours long flight waiting for you…
3. Once arrived in Beijing, the fun part starts
4. As soon as you get off the air plan, turn right when you get into the airport building
5. Take escalator to upstairs
6. Walk all the way till you can see Health Check point on your right hand side, then make a U turn and walk towards Custom
7. Show your passport and the boarding pass at custom (You are at level 3 now)
8. After passing custom, go towards escalator and go down to level 2
9. Take subway to T3-C terminal
10. Walk towards baggage claim
a. If Beijing is your destination, then go outside the building after pick up your luggage
b. Otherwise, after pick up your luggage, then make a left turn, walk a few steps then make another left turn into domestic flight area
11. Take elevator to level 3 and walk toward security check
12. After security check, go towards the boarding area for your flight
a. You may need to use elevator twice to get to level 1, since most of connections are on the ground level by shuttle bus
由北京出关时程序跟上面差不多正好相反，大致情况是这样的：
（所有情况根据2011年初乘坐国航从北京前往旧金山的路线为参考）
1. 从北京首都机场的国际出港通道出发
2. 先过安检
3. 然后下到第二层去坐地铁，前往T3-E站台
4. 下车后上到第三层
5. 准备好护照和航班的登记牌，然后出关
6. 出关后直接前往所乘航班的候机室
English version: From Beijing Intl Airport to SFO
1. Get into International Departure Channel
2. Pass security check
3. Take escalator to level 2, then get on to subway to T3-E terminal
4. Get off subway then get up to level 3 by escalator
5. Prepare passport and boarding pass at custom