There is a waiting list for US EB5 investment immigration. Is it based on submitting application materials or I?

It starts from the date of submission of application materials (I-526).

To be more precise:

1) After USCIS receives your I-526 application, it will fill in a column called Priority Date on your I-526 receipt. A specific date is your priority date.

2) At the beginning of each month, the visa office will announce the EB-5 visa deadline for the next month. For example, the deadline for the EB-5 visa this month (March 2016) is February 1, 2014.

3) If your priority date is earlier than this deadline, you can start the visa interview application process at the consulate (or start the USCIS I-485 review process if you are in the United States); If your priority date is later than this deadline, continue to wait for the schedule