The Amarok RSS feed usage is great. But it would be better if I can to see the text not only listening the songs.
Here is an podcast:
http://rss.dw-world.de/xml/DKpodcast_lgn_de
I can listening it easily that's clear and good, and cool.
But there is some text (the text of speech) in the feed, how can I see this in Amarok?

That is not implemented. I presume you can read the text on the website, no? Of course they could simply configure the text to be sent along as lyrics, then you can read it in the lyrics tab, but currently podcast is purely audio.

I checked that Podcast again, especially the downloadable files for each episode: they are very compressed, contain no tags at all, and it's MP3, so there is no text anyway. I suggest you ask them to make a proper container format that includes the text, best would be to put it in the lyrics tab.

Having this in a better format, like OGG would be preferable, of course.