it's understandable, it happens quite a bit, but it's not very healthy in the counsellor-client relationship.
if you feel you like him a lot as a pdoc, cool. but if it's like him a lot as in "falling in love with him," then it's a no-no, very risky situation. and like mudhound mentioned, you can be taken advantage of if he found out that you were into him (you are in a very vulnerable position). or, he'd tell you that he cannot work with you anymore because it's not conducive to the professional relationship. it's against the law to have a relationship with a pdoc/counsellor so a decent pdoc would let you go if he found out (which is a good thing to do).
BUT, you have to also be aware that this may be the only emotion (if love) that you feel comfortable having towards a person whome you tell your deepest feelings and troubles to. you might truly dislike that, but you feel more comfortable being infatuated/in love by your pdoc than being frustrated/annoyed/confused by being so open with him. (if you told him, he might discuss this issue from this aspect).
make sure you know exactly what you're feeling, and do the right thing. you'll know in your heart what it is once you know how you feel.
take care