Post Preview Problem

Hello.

So, I created some posts. I wrote it like this:

“Code: XXX
Size: XL
Price: 100″

On that post, it is written just like that. But when it comes to the post preview (homepage), it is written like:

“Code: XXX Size: XL Price: 100”

I had tried some html stuffs, like
…</br> or <p>…</p>, but it is just written like that, nothing changes on the post preview. How to make it “normal” just like what I wrote on the post preview?

For the help and answers, I thank you.