The relationship between financial openness and economic growth has been discussed for decades. However, it still remains unclear whether openness has a positive or negative effect on growth. In order to clarify this issue, a right measurement for openness is required to examine its linkage with growth. Several measures (de jure, de facto, and a hybrid between the two) have been used in the literature. To better measure the effect of openness on growth, this paper introduces a new indicator for openness (BOR --- Beneficial Openness Ratio) based on the balance of payment (BOP) statistics. Moreover, annual GNI rather than GDP data are used for analysis since what matters is the real benefit a country can gain from financial openness. Panel data regressions will be run in this paper to detect the relationship between BOR and GNI growth rate, with other factors also included in the regressions as potential determinants of GNI growth rate. A large group of countries are studied included OECD countries, Asian Emerging countries and lower income countries. Positive relationships between GNI growth rate and BOR in OECD countries and Asian Emerging countries were confirmed. However, negative relationship was detected in Lower Income countries. Certain policy implications can also be derived from our empirical results in the end of the paper.