Abstract: Using unary linear regression, the relationship between carbonate content and acidolysis hydrocarbon in a well was investigated, which was different in wells with long production history, dry wells or wells with short production history. The gradient in the mudstone and related coefficient were greater than that in the sandstone in the wells with long production history, but the reverse was true in the dry wells or the wells with short production history. Then the reasons for the characteristics were analyzed from the carbonate mineral formation and the different lithology's adsorption property. According to the characteristics, a new method was developed for hydrocarbon prediction in exploration wells and the re-examination of old wells. This method was fast and with low cost, and could effectively improve the success rate of new and old wells re-examination.