Is he interest in me ?

there is a guy at my job.I am not sure if he is just being nice or what. He always smile and say hi to me every time I passed by. We have each others facebook. and sometime, he would chat w/ me during work hour or after work. He would also ask me my lunch hour and have lunch with me sometimes. He seems like he is concerned about me. one time, my finger got paper cut and he seems worry about me or something. I am not used to guy being nice or concerned about me, so I do know if he is just being nice or actually interested in me.

Hard to tell. If you're interested in him you can always ask him out for coffee, otherwise just play the waiting game and see if he acts on his own.

It is very typical to say about him that he loves you or not. Because care meaning is always not that e loves and all. Sometimes it has another meaning. So don't think too deep just think about him as friend. When he having something for you then he will soon tell you.

i would advice you to take your time and take this friendship further gradually and you will soon get to know his intentions.