airline co-branded credit cards belong to different airlines. When applying, you should consider which airline you often take before applying for a credit card. China Southern Airlines, China Eastern Airlines, Air China and so on have joint credit cards with many banks. Then, the proportion of mileage exchange in each bank is similar. Generally, 16 points for gold cards are exchanged for 1 mileage point, and 14 or 15 points for platinum cards are exchanged for 1 mileage point.