Romantic paintings, Paul Cézanne, Pablo Picasso, pop art and Chinese traditional painting have all influenced Zeng's art at different times in his career, but his work is most heavily influenced by his physical and emotional circumstances. His "Hospital" series, inspired by the scenes he witnessed in the local clinic near where he lived, is considered among his major early achievements, as well as the "meat" series. Both series are influenced by German Expressionism, unlike the landscapes and portraits generally done by his classmates. In his "Hospital" series, Zeng moved to a theme that included the use of hospital interiors, where he devoted much of the detail to the patients' moods and the power that certain brush stroking techniques could yield. These paintings often hinted at a sadomasochistic relationship in the world with his pale colors and blood colored flesh of the patients. In using these techniques, he shows a somewhat pessimistic view of the world. His expressionist technique shined through in these works further with an extreme expression in the eyes of the characters. Also, the hands of the patients are notably oversized and the joints are much larger as well. The scenes he depicts seem to show patients caught up in seeming hysteria, and the deep red colors show anger of sorts.