The two methods for the derivation of helium abundance are presented. The magnitude of the largest bump along the red giant branch is fainter as helium abundance decreases and metal abundance increases. Using this relation and observed bump magnitude, the He-abundances of globular clusters are estimated. The another method is to use the relation that the ratio of asymptotic giant branch and horizontal branch stars increases with decreasing He-abundance. The comparison of the He-abundances derived from the two methods with those derived from the other two methods shows that they are consistent within the dispersion less than Δ Y = 0.1 .

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. THE RELATIONS BETWEEN CHEMICAL ABUNDANCE AND MAGNITUDE OF A BUMP ALONG THE RGB
Ⅲ. DERIVATION OF HELIUM ABUNDANCE FROM THE BUMP MAGNITUDE ALONG THE RGB
Ⅳ. THE DERIVATION OF THE HELIUM ABUNDANCE FROM THE NUMBER RATIO OF AGB AND HB STARS
Ⅴ. THE COMPARISON OF HE-ABUNDANCES
Ⅵ. CONCLUSION AND DISCUSSION
REFERENCES

• Hae-Young Yun(Department of Earth Science, Kyungpook National University)
• See-Woo Lee(Department of Earth Science, Kyungpook National University)