Blasts can be seen erupting from both ground level and from near the top of the building. A witness told local media that she heard several explosions in Wanda Shopping Plaza on Hongqi Street, after which evacuation was ordered. Authorities later confirmed that one person died while another was injured.
Reports from the scene claim a man had been throwing explosives from a high-rise building.
They claimed it could be a terror attack, although this has now been dismissed.
Police have warned people to avoid the area around Wanda Shopping Plaza.
The blasts happened about 2:20pm (0720 GMT) on the 30th floor of the Wanda Plaza Apartment Building, city authorities said in a statement posted on social media, adding that the incident was under investigation.
The first blast happened in a basement car park, while the second happened on the 30th floor of the high-rise building.
Changchun is the capital of northeast China's Jilin province.
