Abstract: An experimental investigation was conducted for the influence on the loading of span by 60° turning angle plane compound lean compressor cascade,which was designed with tangent air injection slots in different inflow incidences.The experimental results show that not only the diffusion factor of cascades is increased and the turning of airflow is improved effectively,but also the static pressure of outlet in negative lean cascades presents a "C" distribution from hub to shroud by tangent air injection.The integration of slots injection and compound lean blade technologies will be an investigation direction in the future.