Abstract: An investigation was made on a long-term fertilization facility vegetable field at Shenyang Agricultural University to study the effects of long-term fertilization on the soil enzyme activities and soil physicochemical properties. Long term application of organic manure combined with or without nitrogen fertilizer increased the contents of soil organic matter, N, P, and K, and improved the soil physical properties and soil invertase, urease, and neutral phosphatase activities. However, longterm application of nitrogen fertilizer alone decreased  soil pH and soil enzymes activities. Significant positive correlations were observed between soil invertase activity and soil organic matter and total P, between soil urease activity and soil organic matter, alkali-hydrolyzable N, total and available P, and available K, and between soil neutral phosphatase activity and soil organic matter, total P, and available K, but less correlation was found between soil dehydrogenase activity and soil nutrients.

Key words: long-term fertilization, soil enzyme activity, soil physicochemical property, tomato, temperature, day and night temperature difference, yield, fruit quality.