It is important to me - usually refers to an event or object and is being specifically referred to. Be careful with that urn. It is important to me. It is important for me - is usually followed by the word to. This is normally going to be an action being referred to. It is important for me to be honest with myself. I hope this helps. Mat

"It is important to me" can be used by itself. It refers to something that is significant to the person speaking. "It" can refer to anything. However, "It is important for me" is usually followed by something else, like "It is important for me to do something. . ." Be careful with these types of phrases. They can change the meaning of a sentence.