In the modern post-WWII era that would be Tibet, Korea, India, USSR, and Vietnam. Maybe also Philippines, depending on what you consider to be an "invasion". Depending on your perspective, China might have had valid reasons for some of those conflicts but regardless of the reasons the fact remains that they at least temporarily invaded territories claimed by numerous other countries. Who's next?

https://pca-cpa.org/ar/cases/7/

Right, an exceptionally short list of relatively minor instances when compared to the US.

Tibet doesn’t count either, it’s been a part of China for centuries and it was the serfs and slaves that sought reunification to escape the monks’ brutal rule.