'List' issue

The script I wish to write as:

private List pokemons = new List();

But ‘error 1303: The name ‘List’ does not exists in the current context.’

I am using unity 5.2.1.

Is that this version of unity not yet have this function?
Any solution for this?

Collections using generics are in the System.Collections.Generic namespace. You’ll need to use that at the top:

using System.Collections.Generic;

In visual studios, right click an error and select the light bulb to try to resolve the error. It will suggest the proper using statement. In mono, they have the same feature, I just can’t recall what option you select.