This paper explores how people perceive about family size and environmental degradation. Many studies explain people perception to family size or environmental degradation independently. Considering both of the concepts as interrelated, how people consider the relation between family size and environmental degradation, and how their perception subsequently influence on contraceptive use in developing countries. People who think their immediate environment such as land productivity, soil fertility, water level and biodiversity is declining are more concerned about their family size and contraceptive use than who do not think that their environment is declining. Children in poor area or forest area are involved with fuel wood and water collection. Parents especially women perceive additional child as helping hand in domestic work or fuel wood and water collection. In reality socio- economic development particularly women education, participation to reproductive decision and access to contraception, and improvement of environmental qualities such as proper sanitation, drinking water, and environmental awareness are important to change people perception to larger family size. As a result people will start thinking that environmental degradation is the result of over access to natural resources.