Is it true that everything is possible?

[阿特拉名贤]

Do you want to know if the summoned spirit can reach every corner of the earth? I am a Chinese. Is it effective to summon goetic spirits in China?

 

[Yazata]

Don't make such vague titles please.
As for your question:
I don't think the Great Wall will prevent them. You can always give it a try and see for yourself (and afterwards maybe share your experiences for those interested)

 

[SkullTraill]

You can answer this for yourself by asking yourself this question: “If I had to live outside China for an extended period of time, would I still practice my Chinese occult practice/religion, or would I have to switch to the occult practice of that region?”

 

[ashlesha]

It depends on the "power" of the spirit. Usually named spirits from grimoires can be conjured from anywhere, since they were perceived by magicians tapping into other subtle spheres of influence. Your local ghost, childhood tree spirits, or village protector spirit will probably not be accessible once you're out of the area.

The Grimorium Verum specifically has seals for Lucifer depending on which continent you're on, along with rulerships for different continents, but even this doesn't seem to matter since his most popular seal is the one for him ruling Asia, yet people get great results in America with it! There's probably some overlap in the hierarchy that we can't (or don't need to) map out from the spirit's perspective.