How can I handle harassment from a biased senior officer?

Hello, I am working for a government PSU and my senior officer is always against me and pick out the little things in my work purposely. He has some kind of personal bias with me not sure because of office politics or whatever. He puts restrictions on everything little thing for me. He intimidates me for writing show causes. He never calls the senior that have more responsibility for work then me. He always calls me and intimidate me for warning memos. I am really fed up with this. Please guide me what can I can do in this situation. It's a clear harassment.