A computing method for ridesharing paths, a computing apparatus and a recording medium using the same are provided. This invention finds the ridesharing paths out from the target trajectory which have ridesharing relationship with a plurality of candidate trajectories. People on the ridesharing paths can share a ride on a part of or whole target trajectory. In the computing method, a trajectory is transformed into a sequence of blocks. After target trajectory and a plurality of the candidate trajectories are transformed, it is determined whether each of the blocks of the candidate trajectories overlaps with at least one of the blocks of the target trajectory. Then, ridesharing paths are calculated according the screened candidate trajectories. This method is many-to-one method which compares a plurality of the candidate trajectories to one target trajectory at one time.