Joint attention has been suggested to contribute to children's development of cooperation; however, few empirical studies have directly tested this hypothesis. Children aged 1 and 2 years participated in two joint action activities to assess their cooperation with an adult partner, who stopped participating at a specific moment during the tasks. Children's joint attention skills were measured by the Early Social Communication Scales (ESCS). Results showed that children's responding to joint attention ability contributed to their successful cooperation in an activity that required parallel roles, whereas initiating joint attention ability contributed to their successful cooperation in an activity that required complementary roles. These results suggest a complex relationship between joint attention and cooperative abilities when considering RJA and IJA separately.