Abstract: The effect of improving the eco-environmental factors of a crop field by a network of shelterbelts is investigated and compared with that of a single shelterbelt. The effect of promoting the growing, development and yield of crop (wheat) was analysed also. The result of analysis is given as follows: (1) The effect of a network of shelterbelt is 10% higher than that of a single belt. (2) The variation of wind direction casts no significant influence on the improving effect of a net with a shape of approximate square. (3) The region of shading effect of a shelterbelt is confined within a distance of 0.5 height of the belt. (4) An effect of lengthening the periods of the nutritive growing and the accumulation of meterial of grain was investigated. (5) The yield of crop was increased by about 5.5%.