Principle purpose of this lecture is to present on flags of South and Southeast Asia. The national flag is a symbol or emblem of a country, and therefor it represents a country. Each country in the world has its own combination of colors, shapes and symbols, but conventionally almost all national flags are rectangular. Like Bangladesh: The flag symbolizes the green field as well as the rising sun. The blood-red color of the national flag bears the testimony of our bloodshed of achieving independence. It also represents the rising sun over the green fields and the evergreen subtropical forests of our country.