The primary purpose of this paper is to estimate scaleheights of
486 southern spiral galaxies by Peng's method and to explore the
correlation between the flatness of a spiral galaxy and the color
index. At the same time, we found some other statistical correlation
between flatness of spiral galaxy and the total "face-on'' magnitude
in the B system, and so on. Our main conclusions are that
flatter galaxies are bluer and look brighter and that spirals
become flatter along the Hubble sequence 
.
Acknowledgements
We would like to thank Prof. Jing-yao Hu for his hospitality and discussion at Xinglong Station of Beijing Astronomical Observatory, and are grateful to Prof. Jie-hao Huang for his much help in English and operating computer. We acknowledge Dr. Qiu-sheng Gu for his much help in operating computer. This work is supported by both the National Nature Science Foundation, National Grand Project "Climbing Up'' of China and the Doctoral programm Foundation of State Education Commission.