Embodiments of the present invention provide an Instant Messenger (IM) and a method for dispatching tasks by the IM. The method includes: presetting task information in a start-up program configuration table, and dispatching, by the IM, tasks in batches according to the task information in the start-up program configuration table. Preferably, the task information includes the execution delay information and priority information of the tasks. The IM includes a logging-on flow management module and a task dispatching management module. The logging-on flow management module is adapted to store the start-up program configuration table, which is configured with the task information. The task dispatching management module is adapted to dispatch the tasks in batches according to the task information in the start-up program configuration table. With embodiments of the invention, the start-up delay of the IM may be reduced.