It is said that CSIRT activities vary depending on the organization, but CSIRT's actually have common challenges, such as “The extent of cybersecurity measures,” "Difficult to gain consensus,” “How to train human resources,” etc. If those challenges are not solved through trial and error within your organization, you can easily get tips by exchanging information with other reliable CSIRTs. The Nippon CSIRT Association's Regional Promotion Committee holds “CSIRT Workshops” in each region of Japan. CSIRTs from each organization can gather and talk to each other, and they can build relationships of mutual trust. This presentation will introduce CSIRT's daily activities and how useful CSIRT communication activities are.