Your son's W-2 income should be entered on his tax return if he is required to file. It is never reported on your tax return.

You can claim your son as your dependent, if he is under 24 and a full time student and if he didn't provide more than half of his total support. 

You can also claim him if he is 24 or older and his income is less than $4050 for 2016 (at this age he doesn't have to be a full time student) and you provided more than half of his support.

If he is your dependent as I explained above, then he would have to file his own return to claim his W-2 if his W-2 is more than $6300.  Otherwise, he doesn't have to file... he may want to - if he had any tax withheld - he would get it all back.