We had a content with two domain. the first domain is my company name. The other have 3 key words in the domain(so this domain have a good rank in yahoo). This state had continued more than 2 years. But now there are may some problem. when search in google. Some times we can't search this first domain index in SERPs. Some times we can see two of this domain in SERPs. And the second domain had higher alexa rank. I am worry about whether will be punished. And wish somebody can tell me should I do 301 redirect for the second domian.
I think it's good for you to optimize the first domain site for better search results rather than redirecting it. Best way to go with update your content and build links, also make sure the content of domain no 2 should be different from domain no. 1 otherwise you'll face duplicate penalty from google.