The study was to find the grey correlation between the performances and 10 disciplines of men's decathletes with the help of the grey relational analysis. Data in the form of scores for 192 performances in the decathlon over 8500 points was collected and then subjected to grey relational analysis. The results indicate the 10 disciplines, can be classified into five factor sets, which the Percent Contributions of five factor sets to the performance are 30.58%, 20.12%, 19.92%, 19.67%, and 9.72% respectively. By comparing the results between the different studies, it was found the decathletes who succeed in decathlon should be all-round development in all the biomotor abilities, as well as to produce technical improvements in all 10 disciplines.