The first object of protection is different: a utility model only protects the shape and structure. In other words, it requires a specific structure. The invention can be a structure, method, use, etc.
The second protection period is different, 10 years for utility models and 20 years for inventions.
The third difficulty of authorization is different. Utility models do not need substantive examination and can be authorized in less than one year. Inventions require examiners to search and review creativity, which may take 2-3 years to authorize. However, the relative utility model rights are not stable enough and can easily be invalidated. The invention is relatively stable.
Utility models are slightly more numerous in number. Because they are easy to authorize, some companies apply for utility models in large numbers in order to be evaluated as high-tech or to obtain policy support.