Abstract: To cope with the negative effect of west-to-east power transmission on the load of power units in Guangdong, the model of generation right trade between trans-province power transmission contract parties is built after necessity and probability analysis on engagement of generation right trade for Guangdong thermal power unit. Then, by taking generation right trade between Guizhou and Guangdong as example, the model is verified, and benefits of both parties are calculated. Results show that the load of thermal power units in Guangdong is greatly affected by external power, particularly the effect on units with medium capacities exceed 5% of generation capacity, which show that it is necessary and probable for thermal power units in Guangdong to engage in generation right trade. Through generation right trade, the benefits of Guizhou province and transmission grid are increased, and the load reduced by above effect of Guangdong thermal generation units can be exploited totally, which compensate 29.7% loss, and the compensation proportion of units with larger capacity is bigger.