Hoang Su Phi, which is the mountainous district of Ha Giang province, have had long traditional Shan tea variety. Due to simple technical practices without fertilizer and pesticide application and only exploit from the nature, this is the strengths in producing safe and high tea quality. However, Hoang Su Phi tea yield is very low compared to country average tea yields by 40 percent and quality is not high as expected. The results from researching several techniques in improving yields and quality concluded that re-planting tea containers needs to have bigger size (the best size of container is 18 x 25 cm)
complementing minimum 20 tons/ha crop residues was good for tea growth and increased yields up to 17.82 percent and improved the soil structure and texture. In addition, the best time period of preliminary withered leaves were done with 4 hours and then destroyed the ferment by stitching or steaming and then dried out to improve tea quality.