Abstract: Major site factors of southern type clones of Aigeiros section were evaluated by multivariate statistical analysis method. The results show that soil availabe water is a major integrated site factor which affects the growth of two clones, its contribution percentage (CP)being44.56% and 34.00% for 1-69/55 and 1-72/58 respectively. The CPof soil physical properties and aeration condition is about 24%, and that of soil nutrient is 10%. The accumulated CPof major site subfaetors including flooding, microtopography, ground water level, management level, soil structure, soil texture, available Kand pHis more than90%. In the end of the paper, table of contribution value including those of site class and quantitative site index is worked out.

Key words: Site quality, Site factor, Contribution percentage