1. Explore the efficacy of Ulinastatin use in improving post-operative pulmonary insufficiency and safety in pediatric patients undergoing scheduled CPB open heart surgery to treat Complex Congenital Heart Disease
2. Explore the efficacy of Ulinastatin use in improving intraoperative hemodynamic instability as well as other post-operative organ recuperation and its impact on hospital stay & cost

Pediatric patients diagnosed with Complex Congenital Heart Disease ready to accept scheduled open-heart surgery under cardiopulmonary bypass (CPB).

This study uses randomized (centralized randomization) & controlled design with open label. Eligible subjects will be randomized to receive either study drug (Ulinastatin) or conventional treatment.

Inclusion Criteria:

1. Children diagnosed with Complex Congenital Heart Disease .
2. Hospitalized children, both gender, aged ≥ 30 days to ≤ 4 years.
3. Preoperative assessment meet with surgical condition.
4. Without signs of Liver, Kidney, and Coagulatory dysfunction.
5. Written informed consent form has been signed by the Legal Guardian.

Exclusion Criteria:

1. Patients will accept minimally invasive surgery or palliative surgery, as well as Major Aortopulmonary Collateral Arteries (MAPCAs);
2. Its decided that subject needs to undergo second surgery in a short period of time, or underwent other major surgery.
3. Subjects with known hypersensitivity to study medication (Ulinastatin for Injection) or patients with highly allergic history.
4. Though meeting the study inclusion criteria, the Legal Guardian reject to sign on informed consent. Or at the discretion of study investigator/coinvestigator that the subjects is not appropriate to be included in the study.