A workshop on "Math of Jets" co-sponsered by RIMS (Kyoto University) and iTHEMS was held from July 29 to 31 at Kyoto University. Researchers from wide scientific fields, such as, planetary atmosphere, astrophysics, quark-gluon plasmas, and so on gave talks. The common keyword for participants are 'jet' and/or 'hydrodynamics'. Since most of participants use numerical hydordynamic or magnetohydordynamic simulations as a tool for their study, some part of discussions are devoted to introduce numerical technique, numerical difficulties and unresolved problems. We enjoyed getting to know research topics and problems in other research fields. At the workshop banquet, one of participants said as a speech "Recently the borders between countries have not been so high but the borders between scientific field have been getting higher and higher, event if they have common language, for example, 'hydrodynamics' like us. We should continue this kind of workshop. Otherwise, we can not understand each other in near future." The workshop was good opportunity to interact with other fields and we hope we will have next meeting in near future.