The invention relates to a composition for improving yield and quality of crops. Active components of the composition comprise choline salt and DCPTA (2-(3,4-dichlorophenoxy)triethylamine) in weight proportion of 100:1-1:10. The composition has synergistic interaction, and is suitable for increasing production of food crops, vegetables, oil crops and fruiters and capable of improving the quality of the crops. The composition is simple to operate, can be used singly or mixed with chemical substances such as a fertilizer, a microelement, vitamin, amino acid, a pesticide, a bactericide, an acaricide, a plant growth regulator and the like. The composition can be applied to the soil or the seeds, leaves, fruits and branches of the plant by using the normal application mode in the agriculture.