ZigBee is an IEEE 802.15.4-based standard for wireless sensor network. The operations of ZigBee rely on the deployment of wireless sensor devices and their self-organized network connections. In some of applications, sensor devices are randomly deployed and some of these devices may become isolated from the network due to the constraints of ZigBee network configuration parameters. The isolated devices will cause the expected network operations unreached and waste the corresponding deployment costs. This paper proposes a connectivity improving mechanism which utilizes a connection shifting scheme to increase the join ratio of deployed devices for achieving the expected ZigBee network operations and consequently reduce the waste of deployment. The result of network simulation shows the connectivity was improved in ZigBee networks by using the proposed mechanism.