Sixty cases of infertility due to luteal phase defect were treated with herbs to tonify the kidney and regulate the menstrual cycle. After the treatment, the hyperthermal phase score of basal body temperature (BBT) was markedly increased (P less than 0.05), the hyperthermal phase 7-8 days after ovulation improved (P less than 0.001), the transitional period of BBT remarkably shortened, and the pregnancy rate in 32 uncomplicated cases of luteal phase defect was 56%. The close relationship between luteal phase defect and the kidney deficiency syndrome in TCM was discussed. The key points of the treatment included coordination of yin and yang, regulation of qi and blood, and combination of tonification with reduction.