請問：Chinese visa or travel doc for my son

Hi, Teacher 8 or other experts, my son was born in the States, and both parents have I-485 pending with I-140 approved. When I take my son back to China, should I apply for him the Chinese visa or the Chinese travel document?  

I got confused by the instructions on the embassy website in Chinese and English: 

http://newyork.china-consulate.org/eng/lsyw/lszjx/*****qz/cccbu/

 

http://www.china-embassy.org/chn/qzfw/sqzn/zmgcs/

Many thanks in advance!