Smoking induces substantial diseases on both individual and the whole society. To identify the true smoking-attributable economic loss, we introduce medical cost accounting as a means to calculate disease-specific medical cost, including inpatient and outpatient cost of those diseases caused by smoking. Medical cost is defined as health resource consumption in terms of money. Cost is allocated to department and services according to coefficient of benefit and operation time. The study in 1988 indicates that total smoking-attributable medical cost is 2.32 billion RMB Yuan in China, 1.70 billion RMB Yuan for outpatient, 0.62 billion RMB Yuan for inpatient. If indirect cost is included, the cost will be greater. Chronic obstructive emphysema has the highest proportion (55.41%) in smoking attributable medical cost.