[client21]

For example we have native "MyNative" (CreateNative).
It created in other plugin or exstension.
We can know who created this native?

[Fyren]

An extension could probably iterate plugins and check each to see if a native with the right name exists. Off the top of my head, that's the only relevant exposed functionality.

Why do you want this?

[Reiko1231]

Extending Fyren answer, you can probably iterate plugins with SourceMod using GetPluginIterator, MorePlugins, ReadPlugin and check plugin for native using GetFunctionByName.

[Peace-Maker]

That wouldn't work, since the function you register as native callback in CreateNative has a different name than the native itself. You can't access the list of registered natives by a plugin from within a plugin.
Again, what are you trying to solve with this?