Two cases of myxoid leiomyosarcoma of the uterus were reported. Case 1 was a 59 year-old female who complained of suprapubic mass for 1½ months. She had TAH and tumor mass located on anterior wall of the uterus was 12×10×9㎝. Case 2 was a 76 year-old female who found a mass in the left lower quadrant of abdomen. She underwent TAH with bilateral adnexectomy. The tumor mass showed myxoid appearance with cystic change. Microscopically two cases showed spindle to ovoid neoplastic cells in myxomatous stroma with microcystic spaces. Our cases have 0~1 mitotic figure per 10 HPF. Case 1 was lost to follow up and case 2 has been living healthy for 2 years and 1½ months after operation without local recurrence or metastasis. We consider this neoplasm to consist of heterogenous group of low grade and high grade malignancy of smooth muscle origin.