In this study, research of changing with aging of other antioxidants and Coenzyme Q10 which has a strong antioxidant with lipophilic structure and also has an important role in providing energy to chemical reactions in the body was aimed. Research included 160 men and women who have age from 20 to 70 years old and also live in Gaziantep area. Research was done by dividing age groups to 3 groups: 50 people to 20-30, 75 people to 31-50 and 35 people to 51-70 ages. Groups are chosen from among persons who non-obese and do not have any physical complaints. In addition, people in research were checked by looking at their routine biochemical parameters in case to investigate that they are healthy or not. In taken serum samples malondialdehyde, total antioxidant level, paraoxonase and arylesterase was measured, however in plasma sample coenzyme Q10 was measured. The level of malondialdehyde by thiobarbituric acid method, total antioxidant levels, paraoxonase and arylesterase with spectrophotometric method and coenzyme Q10 by the HPLC method were measured. A correlation was found between age and coenzyme Q10 in our study (P<0,001). Coenzyme Q10 was increased with aging. Statistically significant and negative linear relationship was found between coenzyme Q10, paraoxonase, arylesterase and malondialdehyde (P<0,01, P<0,001). People in 31 - 50 and 51 - 70 age groups have higher total antioxidant levels in compare to 20 - 30 age group (P<0,05). Despite the aging, the antioxidant system in healthy people works to protect the body from the oxidants. Level of antioxidant during illness in healthy people not prevent the rising of oxidant. Aging is not a disease. But a disease accelerates people aging process. Therefore, one of the two different people with the same age group, seemed too young and healthy,the other people seems older. [ABSTRACT FROM AUTHOR]