According to 337 investigation cases, this book analyzes patent data in investigated companies, patent data in investigated products, patent data in investigated products of technical branches from commercial database. The conclusion is: which investigated products had strong protection; which investigated products had taken joint protection in China; which IPC in every company had strong protection; which IPC and products except investigated products in every company had strong protection; the impact on the investigated companies and the products after 337 investigations ; which patents are the core patents and litigation patents.