Abstract: Diamond Films have many particular properties and a very wide field of applications in high-tech fields.Patent technology of diamond films in worldwide over recent twenty years was introduced in this paper.The development and competition pattern of diamond films in worldwide were investigated on quantity and quality analysis.Results show that diamond films technology in worldwide has been at a more mature stage,tools-class and heatsink-class diamond film products have entered a practical stage,optical-class and devices-class diamond film technology is not yet mature,technology of the United States and Japan is preponderant,the diamond film market of Germany,the United States and Japan was optimistic competition in application fields is different and the core patents about relevant areas are presented by cited analysis.