This study has been measured the advertising expense efficiency to sales of the separation of prescribing and dispensing before and 10 years later and presented the efficient advertising expense management plan based on the results of the measurements. The analyzed pharmaceutical companies were 33 companies in 1999 and 37 companies in 2010 and all of them were advertising spending most companies. And the advertising expense of Korea Advertising Data(KADD) and the sales data based on published financial statements were used for measurements. The variables for measurements were chosen based on previous studies, and the input variables are advertising expense of TV, Radio, Newspaper and Magazine in 1999, and of TV, CATV, Newspaper and Magazine in 2010. The sales data were used for output variables. The results of this study showed that the overall advertising efficiency in 2010 compared to 2009 declined significantly. And those showed that 22 pharmaceutical companies can expect positive impact on sales in increasing of advertising expense through economy scale in the future, 9 pharmaceutical companies can make advertising expense efficiency through decreasing of the present advertising expense and 6 pharmaceutical companies was considered a reasonable level of current advertising expense. It might be very useful and significant that the results of this study preset the guideline for advertising expense management plan of those pharmaceutical companies in the future.