Humor is an often occurring phenomenon in everyday conversations. In this book, three fragments of conversations which contain conversational joking were analyzed. The result showed that the success of evoking and developing conversational joking relied heavily on the conversationalists'' shared knowledge schemas and their tacit agreement. It was also found that the conversationalists who co-constructed conversational joking successfully usually followed the cooperative principle, as how they did in serious conversations. Hence, the funny story they created made some kind of sense. Co-constructed humor is like a kind of game in which speakers create sense in nonsense together to have fun.