In order to study power output characteristics and interrelatedness of intensive large-scale wind farms located around coastal areas, the large-scale wind farms sit at coastal areas of Jiangsu were taken as an example and some work was done. Based on the field measurement data of output wind power from the EMS system, active power correlation, probability distributions and the monthly maximum output power among wind farms were analyzed. The fluctuation of wind farms output active power was studied and the impact of output active wind power on the composite load of Jiangsu as well as on peak-load regulation was discussed. This work is important for the utilization rate improvement and dispatching optimization of distributed new energy.