The differential diagnosis of benign and malignant ascites is of great significance in clinic; the early diagnosis of malignant ascites is especially difficult. Definite diagnosis is usually based on conventional cytology to find cancer cells in the ascites in clinic, but the rate of missed diagnosis is high, and the negative outcome cannot exclude the presence of tumors. Currently, many new laboratory methods and indicators have been used clinically and have demonstrated primary efficiency in providing evidences for differential diagnosis of benign and malignant ascites.This article reviews the progress in laboratory indicators for differential diagnosis of benign and malignant ascites.