Abstract:In every mid-December of 2009 to 2016, the annual growth of diameter circumference of 1740 ramets in 364 samples of Wickham germplasm resources from four countries preserved in 2008 by the Germplasm Repository of Rubber Tree (Hevea Spp.) Jing Hong City, Ministry of Agriculture, was made a tracing observation. Besides, the height under branch, trunk straightness, stem branching, lateral branch wheel, lateral branch thickness, lateral branch angle and lateral branch stretch were also observed by the end of December 2016. The diameter circumference annual growth rule and variation were analyzed based on investigating data from the samples of 364 Wickham germplasm resources, and the genetic diversity of eight indexes was calculated and multi-index comprehensive clustering was analyzed from the prospective of genetypes and countries respectively. The research was to provide a theoretical basis for revealing their genetic diversity and reasonable protection and utilization. According to the diameter circumference, 364 Wickham germplasm resources samples could be divided into 3 groups, they are slow-growing type (diameter circumference<50 cm), middle-growing type (in the range of 50 cm and 60 cm ) and fast-growing type (>60 cm ), respectively, among which the total growth averaged in 52.88 cm at the age of 8 with an amplitude of variation in 41.50 to 64.00 cm. The average total growth in slow-growing type was 47.49 cm and the amplitude of variation was 40.50 to 49.75 cm, it was 54.02 cm at variation amplitude of 50.00 to 59.75 cm for middle-growing type and 61.07 cm at variation amplitude of 60.00 to 64.00 cm for fast-growing type. The difference of average value was 13.58 cm between the fast-growing type and slow-growing type. From the degree of variation, the amplitude of annual variation coefficients were 10.87 %-25.81 %, 10.20%-26.89%, 9.32 %-25.62 % and 8.64 %-20.78 % for total, slow-growing, middle-growing and fast-growing, respectively. With the forest getting old, the annual increment and annual average growth of three groups all showed a trend of increasing first and then decreasing, and both intersected only once at the time of 3a-4a during the eight years, the fast-growing type intersected more lately. Correlation analysis of diameter circumference annual growth showed that there was an extremely significant positive correlation between slow and middle group (excepted the 1a and 8a from middle group). That of fast-growing group also reached an extremely significant positive correlation at the age of 3. Eight indexes of genetic diversity were orderly from large to small: height under branch(1.835)>diameter circumference growth(1.713)> lateral branch wheel(1.222)> lateral branch thickness(1.192)>lateral branch angle(1.079)> trunk straightness(1.032)> stem branching(0.991)> lateral branch stretch(0.579. Most genetic diversity indexes were comparatively smaller. Clustering results showed that germplasm from the same country were mostly gathered in a group or several groups. Indonesia and Malaysia had the closest relations in four countries, the second was Indonesia and China, and Sri Lanka was farther. In conclusion, the variation of eight indexes from Wickham germplasm resources which preserved in China was not significant, and the abundance of genetic diversity was low. In the very early selection, it was recommended that eliminating choice at smaller forest age (such as the age of 2), and fast-growing resource option at larger forest age (such as the age of 4). Seven samples from fast-growing type germplasm resources can be used for cultivating the latex/timber clone or hybridizing as parent materials.