AbstractBased on the high‐speed video observations obtained at the Tall‐Object Lightning Observatory in Guangzhou (TOLOG), the attachment processes of three lightning flashes seem to belong to the connections between “the lateral surface of negative leader and positive leader tip” which had never been reported before were investigated. The leader connection processes of these flashes were examined in detail, and a mechanism behind connecting behavior between the lateral surface of negative leader and positive leader tip was discussed. Observation shows that negative leaders usually have abundant branches. Although some may extinguish, they still maintain a certain conductivity. When the positive leader tip comes close to the lateral surface of the negative leader (usually a few tens of meters), the previously disappeared short branch can be reactivated. It is easier for the positive leader tip to connect the tips of these branches (whether they have been extinguished or not).