This study was conducted with the purpose of determining the accumulation of lead (Pb) in cultivated soil and three selected vegetables. Seventy five farmers who planted three selected vegetables (jute, basella alba, and bitter melon) along Cau river in Tuc Duyen ward were randomly selected for the study. | Nguyễn Ngọc Sơn Hải và Đtg Tạp chí KHOA HỌC & CÔNG NGHỆ 85(09)/1: 111 - 117 FACTORS AFFECTING LEAD ACCUMULATION IN CULIVATED SOIL AND VEGETABLES IN TUC DUYEN WARD, THAI NGUYEN CITY, VIETNAM Nguyen Ngoc Son Hai1, Chanchai Sangchayoswat2, Attachai Jintrawet2, Nguyen Ngoc Nong1* 1 Thainguyen University of Agriculture and Forestry - TNU 2 ChiangMai University, Thailand SUMMARY This study was conducted with the purpose of determining the accumulation of lead (Pb) in cultivated soil and three selected vegetables. Seventy five farmers who planted three selected vegetables (jute, basella alba, and bitter melon) along Cau river in Tuc Duyen ward were randomly selected for the study. Primary data were collected through formal interview questionnaires and field survey. The data from field survey and formal questionnaires were analyzed using factor and multiple regression analysis to determine the factors affecting Pb accumulation in cultivated soil and the three selected vegetables. The main cause leading to the Pb accumulation in vegetables highly due to vegetables absorbed Pb from farming environment, especially from cultivated soil environment. Cultivated soil environment in the study area effected by the supplement of substances containing Pb such as irrigation water source contaminated by wastewater sources from sewage sludge, residential waste water, industrial waste water, etc. In addition is the solubility of Pb in the acidic cultivated soil environment. We recommend that key stakeholders must be participated in decision making process to reduce the accumulation of lead in both vegetables and cultivated soils in Tuc Duyen ward. Key words: Accumulation, lead (Pb), factor analysis, multiple regressions, vegetable, soil. INTRODUCTION* Thai Nguyen province is an industrial center in northern region of Vietnam. It is the headquarters of many factories, enterprises, many major universities, colleges, schools and large hospitals. Thai Nguyen city is located on the bank