Hi, could you advise how much time i should allocate between an international and domestic flight

Hi, i will be arriving in shanghai from singapore at 620 am in the morning. I was thinking of booking a domestic flight to xian from shanghai and wonder how much time I should allocate between transit. There is a flight from shanghai to xian at 750 am in the morning. Was wondering if there is sufficient time as I was thinking of leaving my luggage at left luggage section as well.