I find that most traffic come from mobile nowadays, so recently I have made a mobile site for my website by using wptouch plugin in wordpress. However, I find that there is no increase in ctr after changing to mobile site. What ads format is the best for mobile site to get higher ctr?
Here is the answer for your query: https://support.google.com/adsense/answer/68727?hl=en&ref_topic=23384 and https://support.google.com/adsense/answer/185668?hl=en&ref_topic=29561, You can also use Mobile Leaderboard (320x50) and Small Square (200x200) for better results. Some themes (if you are on Wordpress) do support both responsive and non-responsive ad units where you can have two different codes, so the theme itself decides to display whether to display mobile ad unit or normal desktop ad.