In the first major international athletics event since the Olympic Games, 576 athletes from 127 countries will contest 26 events over the next three days inside the city's Nanjing Cube.
Great Britain will have 11 athletes competing in China after George Mills and Innes Fitzgerald both withdrew through illness and did not travel with the team.
They join Keely Hodgkinson on the sidelines after the 800m star suffered a hamstring injury ahead of her inaugural event, the Keely Klassic, last month.
Mills was among the favourites to medal in Nanjing after winning silver in the men's 3000m at the recent European championships, while Fitzgerald was slated to contest her first international competition after finishing inside the top eight on her senior debut in Apeldoorn.
Although their loss will be a huge blow for Great Britain's prospects in China, both will now focus on the outdoor season which leads to the World Championships in Tokyo this September.
"I was really looking forward to this one and felt it was my first opportunity to really mix it on the world level," lamented Mills on Instagram.
"As much as I want to travel, put myself on the start line and just try, I have to listen to my team and respect our long term goals."
Elsewhere the hundreds of athletes who did travel - including 20 medallists from Paris 2024 and nine word record holders - have been busy putting finishing touches to their preparations during a hectic final training session inside the city's 13,000-seater arena.
Among them was reigning Olympic and World Indoor champion Thea LaFond.
The triple jump star made history in Paris to become the first athlete from Dominica to win an Olympic medal, but now admits the pressure to succeed has only increased since winning gold.
"A lot has happened since the Olympics," she told reporters. "I had knee surgery two weeks after I won gold, so not only is this my season opener, it is my first time back since having that knee surgery.
"It really brings in all the feels. I am so grateful, and I've truly just learnt how to love the sport even more since the Olympics.
"Gold is not enough anymore," LaFond joked. "It would be incredible (to win back-to-back indoor titles). All I really want to do is to make Dominica look good. If I can do that, I am more than happy."
Meanwhile Canada's Sade McCreath, who will compete in the 60m after finishing outside the medals in the 4x100m relay at Paris 2024, said there is almost no margin for error over the shorter distance in China.
"It's the idea of being perfect indoors," McCreath explained. "It's such a short race, it's only 60 metres, it's such a short space, you don't have time or space for errors.
"The moment the gun goes, it's all out, close to perfection. Hopefully, you execute everything that you need to. In a 100m, you can kind of not have the greatest start and kind of come back. In a 60m race, the margin for error is very small.
"We’re definitely going to see some great times, I know that for sure."