Adopting field investigation and indoor analysis, the changes of soil water-stable aggregates distribution and the driving forces in the conversion of paddy field to tea garden were examined. The results showed that soil water-stable aggregate in the paddy field and tea garden was different among different size class and soil layer. With the decrease of the particle size, the water-stable aggregate firstly decreased and then increased in paddy soil and tea plantation with 5 years, 10 years. In the 15 years tea garden, water-stable aggregate was increased with the decrease of the particle size. With the increasing years of tea planation, water-stable aggregate was given priority to ＞2 mm turn into ＜0.25 mm both in 0—20 cm and 20—40 cm soil layer, while ＜0.25 mm water-stable aggregate was the predominant contributor in 40—60 cm soil layer. The water stability of soil aggregate decreased with the increasing years both in 0—20 cm and 20—40 cm soil layer, whereas the ranking from high to low in 40—60 cm soil layer was: tea plantation 5 years＞tea plantation 10 years＞paddy field＞tea plantation 15 years. The stability water of soil aggregate was positively correlated with the content of ＞0.25 mm water-stable aggregate. The water stability of soil aggregates was positively correlated with the soil chemical properties, and the main driving factors were ＞0.25 mm aggregates, soil bulk density and total porosity. In terms of nutrients, the driving forces of water stability in paddy field, tea garden 5 years, 10 years and 15 years were organic matter, organic matter and CEC, organic matter, CEC and effective phosphorus content, content of CEC, respectively.