Abstract: Good quality of patent licensing would stimulate company to continuous innovation, realize the commercialization and industrialization of patented technology. However, corporate irresponsible behavior has frequently occurred, which caused a series of social problems and played a negative impact on the cooperation of patent licensing. Thus, a series of documents have issued to encourage enterprises to fulfill corporate social responsibilities (CSR). When branded manufacturer fulfill corporate social responsibilities, does the CSR investment really help to improve product quality? How to design the patent licensing?
Focusing on these questions, a two-stage game is built to describe the operations of patent owner and branded manufacturer in the presence of asymmetric information and corporate social responsibility. In the first stage, the patent owner design the patent licensing and license its technology to branded manufacturer; In the second stage, the branded manufacturer use the technology to produce products and sell them to consumers. In this model, it is assumed that the product demand may be in two different ex ante quantity states:high and low. The true product demand cannot be observed by patent owner, but branded manufacturer can learn. The patent owner design the patent licensing to branded manufacturer in different product demand, then branded manufacturer use the technology to produce and determine the product quality and sale price. Finally, it is assumed that the branded manufacturer is equipped with CSR preference which is represented by the degree of branded manufacturer cares about consumer surplus.
The analysis process is as follows. Firstly, we examine how CSR investment affect the patent licensing and product quality; Secondly, analyze the effect of CSR on the profit of patent owner and branded manufacturer; Finally, investigate the influence of CSR on consumer surplus and social welfare. The results show that:Patent owner would design the licensing contract of ‘fixed-fee’ in high product demand and ‘two-part tariff’ in low product demand; The CSR does not affect the form of licensing contract, but increase the fixed fee; A higher of product demand leads to a higher level of product quality, consumer surplus and profit for patent owner, but may not a higher level of sale price; CSR investment helps to enhance the product quality level, consumer surplus and the profit of patent owner, but decrease the profit of branded manufacturer; In the whole, the CSR investment has a positive impact on social welfare.
The innovation of this paper, is not only extends the research of patent licensing and reveals the impact of corporate social responsibility, but also provides a theoretical basis for decision-making of patent owner and branded manufacturer.

Key words: corporate social responsibility, patent licensing, product quality, asymmetric information