Von Bertalanffy equation was analyzed in theory and compared for fitting with a lot of present data between the power2exponential equation of growth and von Bertalanffy ’s. It was discovered that power2 exponential growth equation was more applicable and fitting than von Bertalanffy’s and was also deduced by modifying von Bertalanffy equation. Comparing with other eight growth mathematical models , the relation index for fitting and applicable range of the power2exponential growth equation was the best in all models.