The average human lifespan was around 35 years in 1950 and is now 72 years, but is still much less than the longest record of 122 years. Likewise, the present human lifespan differs as much as 30 years across the world. These differences are due to many factors such as meals, obesity, and diseases. This book clarifies these factors and suggests means for the general population to live longer. Related to this, it also reports the status of centenarians in the world and animal experiments.It provides a survey of lifespan records of animals and plants and related factors, especially genes. The results indicate that there are both plants and animals living for 10, 000 years or longer, which will be interesting to researchers and students.