For the same thing, such as a chair, some people apply for utility model patents, while others apply for appearance patents. What should I do?

Legally speaking, the utility model protects the structure and function, while the design protects the pure appearance that does not involve the structure and function. The scope of protection of the two is different and cannot be compared.

If you think your product has some advantages in structure, function and appearance, then you can apply for two patents. And if you think that structure and function are more important, as long as someone else adopts a structure similar to yours, no matter what appearance he uses, it will be regarded as infringing your patent right. And if you apply for a patent for utility model instead of a design patent, then others take not your structure but your appearance, so it is not infringement.

It's a bit awkward. I don't know. Is that clear?