<正>介绍了上海国际航运中心一期工程工作船码头施工控制测量和沉桩定位的方法，分析利用该方法进行定位的精度，进而阐述用GPS进行码头沉桩定位的可行性和优缺点，并提出了解决GPS沉桩定位的方法。

Genetic variations of growth traits,wood basic density and tracheid length of Chinese fir clones were investigated in this paper. The results indicated that the five traits like height,diameter at breast height, volume, wood basic density and tracheid length showed at least significant genetic variation among clones. They were under moderated genetic control with clone repeatabilities of 0. 771,0. 651,0. 566,0. 529 and 0. 495 respectively. Height, diameter at breast height and volume had a negative genetic correlation with wood basic density and tracheid length. The negative genetic correlation was also found between wood basic density and tracheid length. Two superior clones were selected for fibre wood use based on multiple traits combined index.