Abstract: The turn-over channel of turbine blade is an important part of the internal cooling structure of the turbine blade. Its flow performance is important for the design of cooling structure of the turbine blade. In this paper,a real turn-over channel of turbine blade is simplified and experimental study has been conducted. The paper demonstrates the investigation of the flow performance in a 180° turn-over channel with 90° parallel ribs and 60° parallel ribs respectively. The efficient pressure distribution was obtained along the channel in the inner part of these two turnover channels with 90° and 60° ribs is similar. Some efficient pressure increases along the channel due to irregular change of the channel shape. Correlation formulas of the coefficient of the efficient pressure are derived in the paper.