i dont know why my ad was not aproved?
If the ad is been created for the first time it takes 4 Hours to 24 hours time frame for the review.
And if it is disapproved
Please look in to the policy details in your Adwords account.
Step 1: Go to ad level and click on the columns tab select the Modify columns option.
Step 2:In attributes please select policy details and that will show the reason.
Hope this helps