They arrive on Saturday before the start of three days of events on Monday, with coach Tang Hon-sing determined to avoid putting any unnecessary pressure on the squad by predicting how many medals they will win.
At the first Games, held in Singapore four years ago, high jumper Jessica Fung Wai-yee and long jumper Matthew Pang Ying-kit both won silver medals, but were Hong Kong's only athletics medallists.
"It's great to win medals in the finals, but I want to avoid setting a specific medal target for our young athletes," Tang says.
"We don't know exactly who they'll be competing against. So I prefer our athletes stay focused on their own personal targets - whether that means clinching a medal, reaching the final, or simply recording a new personal best in their event."
However, Wise Poon Hang-wai, who won the girls' 100metres at last year's 46th International Children's Games in Daegu, South Korea, is one athlete with a real chance of winning a medal.
Wise, 15, a Form Three student at Good Hope School, also broke the Hong Kong junior record with a time of 57.12 seconds in the women's 400m event.
She hopes to run the 400m at the Games in about 58seconds. "I'm still trying to improve my form so I'm not setting myself a really fast time as a target," she says. "If I feel good on the day, I'll push myself to run a quick time."
Wise will also run in the 200m. "I am more confident about finishing in the top three in this shorter race," she says.
"I'm going to try to finish in around 25seconds. I ran a personal best of 25.15 seconds at this summer's Hong Kong Games."
Yoyo Chan Hiu-yan, 15, a Form Four student at TWGHs Lui Yun Choy Memorial College, will compete in the 800m.
"I've never been part of a competition that's as big as the Games," she says. "I've been trying to train in the sun here in Hong Kong, so I'm ready to compete in the hot weather conditions expected in Nanjing.
"I've been working on improving my endurance over the past month and think I will be competitive in the race."
Tommy Lee Hong-kit, 16 - the only boy in the team - will run in the 100m sprint. He has a personal best of 11.12 seconds.
He is the reigning inter-school champion in both the B-grade boys' 100m and 4x100m relay events; no sprint relay events will be held at the Games.
"This is my second overseas tournament," says the Form Three student from Diocesan Boys' School.
"Last month, I raced in an event in Vietnam with older junior athletes. My roommate, 800m runner Chung Man-kin, offered lots of good advice."
Other members of Hong Kong's team include Kong Chun-ki, who will run in the 100m and 200m, and Chan Ka-sin, who will compete in the 100m.
The lone field event competitor is Wong Pui-ling, who will take part in the high jump.