how is my arabian's conformation?

What a cutie! I'm usually not a fan of Arabians but he is gorgeous.

I'm no conformation expert, but what I see looks good. He has a straight back, sturdy shoulders and it looks like his legs are aligned well (aka no toed-out or bow legs) The only thing I see is his hooves look long and his heel is a little low. Often low-heeled horses can get navicular or ringbone easier, but good farrier work can help fix that. I'd just have a farrier check his hoof axis to make sure it is not a problem. Otherwise, he looks great - lean, sturdy, nice proportions. :)

Well first I'd like to say he looks great for a 14 y/o. Any who, I have to agree with the above answer, overall he is a looker; I like his head and how it ties into his neck, his shoulder looks sturdy, and his back is nice and straight. His heels are rather low, (I would recommend them being addressed by a farrier if you wish to avoid future lameness issues) and his front legs are a little too straight for my taste, but those seem to be the only 'flaws' that stand out to me. If you intend to show him at halter in a lower level (open/schooling shows, local shows, 4-H) then he is perfectly fine. Overall, he is a good looking little guy.

Happy showing!