Abstract:Different levels of potassium fertilizer were used to study the effect of potassium fertilizer on stem diameter and plant height of waxy maize. The results showed that the stem diameter and plant height of waxy maize increased with the growth period and reached the maximum during the tasselling stage and then remained unchanged. Furthermore, potassium fertilizer could increase the stem diameter and plant height in a dosage dependent manner at the same growth stage. In addition, there was significant positive correlation between potassium fertilizer, stem diameter and plant height (r > 0. 8) , respectively.