Tranexamic acid has been used in surgery for more than 30 years. It's effect on reducing bleeding and blood transfusing has been demonstrated.

In our hospital, the amount of cytorsductive surgery for ovarian cancer is big. During the perioperation , bleeding probability is high, and the supply of blood products is limited. In order to reduce bleeding, we're planning to use tranexamic acid in the operations.

In this experiment, we will observe the efficacy of tranexamic acid in cytoreductive surgery for ovarian cancer, find the best dosage which can reach the desired effect, and the possible side-effect.

We performed a single blind, prospective, randomised control trial (RCT) . The patients randomised assigned to three groups. Low dose TXA, high dose TXA or a placebo of IV saline which will be infused prior to skin incision in patients undergoing elective cytorsductive surgery for ovarian cancer .

Intraoperative blood loss will be estimated by the volume in the suction drains and by weighing the swabs. Postoperative blood loss will be estimated by the volume in the drains.

The other secondary outcomes will be inclued perioperation transfusion volume, thromboembolic complications, ICU length of stay (LOS), hospital LOS, adverse thrombogenic events within 30 days, 30-day all-cause readmission and so on.

Inclusion Criteria:

1. sign the informed consent
2. Aged 20-70 years
3. ovarian cancer patients, staged IIIB - C or above

3) ASA I - II

Exclusion Criteria:

1. tranexamic acid allergy
2. pregnancy and lactation
3. only lymph node metastasise
4. history of mental disorder, immune system disorder
5. history of epilepsy, dyschromatopsia
6. arrhythmia
7. history of renal insufficiency
8. thrombosis related disease
9. Hb < 90 g/dL
10. using anticoagulant drugs (not including aspirin discontinuation 1 week
11. having participated in other clinical trials, or refusing to join the research.