Nanchang Zoo (南昌动物园) in the Xinjian district is a reasonable zoo by Chinese provincial standards, with a reasonably sized collection of animals including giant pandas, which are a reliable draw. The facility has been upgraded considerably in recent years, and the enclosures are larger than the cramped concrete pens common in older Chinese zoos. It's a good option if you're traveling with children, or simply want to see giant pandas without the queues of the larger facilities in Chengdu.
The zoo is set within the broader Wanshoucheng amusement area in the north of the city, with additional rides and family attractions nearby. Admission includes the main zoo; panda viewing may require an additional ticket during peak periods.