In the past, researches on livelihood tended to focus on such issues as survival and living standard, development opportunity and capacity, as well as rights protection. Apart from those issues, in fact, productivity, infrastructure and social institution also play important roles in promoting peoples livelihood. Based on statistics, this paper proposes a new theory of peoples livelihood development, which aims at the establishment of a sustainable development system of peoples livelihood, society and productivity, taking double engines of peoples livelihood and productivity development as the core. Based on the international competitiveness of peoples livelihood development index conducted in 59 countries from 1996 to 2014, it is shown that developed countries generally enjoy a high level of peoples livelihood, and values determine a countrys development pattern. Countries trying to catch up with the developed countries have their own advantages in some fields. While China has achieved considerable progress in employment, education and infrastructure, yet social security system, sanitary and medical services and leisure remain its deficiencies in peoples livelihood development. Whats more,  ecological deterioration, income inequality, social institutional environment changes do not contribute favorably to peoples livelihood development.