Abstract: In northern China, the potassium content was always not enough for plant growth in soil, which was a main factor affecting tobacco production. That the potassium was not enough in soil will not be solved well in the near future. Different tobacco varieties had different potassium utilization ability, which may be one of ways to solve the problem. Looking for economic characteristic related with potassium utilization, using these economic characteristic to select high potassium utilization materials can shorten the selection process. The correlation analysis of some economic characteristic of 19 materials and potassium content was studied. Results showed that potassium content and plant height, stem girth, step, leaf number and the biggest leaf length was positive correlation. The correlation between plant height, stem girth and the potassium content had reached significant level. The correlation between the biggest leaf length and potassium content had reached marked level. Nicotine content was also studied. Results showed that nicotine content of upper leaves and middle leaves increased with leaf age. When leaf age was 75 days, the nicotine content reached the biggest. After 75 days, the nicotine content decreased with leaf age. Potassium content of tobacco was always decreasing with leaf age. For bottom leaves, the nicotine content reached the biggest when leaf age was 60 days. After that, the nicotine content decreased with leaf age. The potassium content of the tobacco was always decreasing with leaf age. The correlation between potassium and nicotine content of leaves were negative. It suggested that nicotine content decreased with potassium content increased in the whole life of tobacco. Increasing potassium content can improve the tobacco quality.