A tape loading mechanism for a magnetic recording and reproducing device to pull out a magnetic tape (14) from a tape cassette (11) containing the magnetic tape to wind the magnetic tape for a prede­termined winding angle around a rotating cylinder (18) having a rotating head mounted thereon comprises incoming-side tape pull-out guide device (15, 17, 41, 47) for pulling out the magnetic tape (14) from the tape cassette (11) to form an incoming-side portion of a tape running path located between a tape incoming side of the rotating cylinder (18) and the tape cassette (11) upon loading the tape (14), the incoming-side tape pull-out device (15, 17, 41, 47) having a plurality of tape guides (15, 17) which are inserted into an opening of the tape cassette (11) to be engaged with a base side of the magnetic tape (14); first outgoing-side tape pull-out guide device (19, 21, 22, 23, 27, 57, 58, 59) for pulling out the magnetic tape (14) from the tape cassette (11) and winding the tape (14) for a predetermined angle around the rotating cylinder (18) downwardly in a spiral form upon loading the tape (14), the first outgoing-side tape pull-out guide device having a first inclined tape guide (23) to change the running direction of the magnetic tape (14) upwardly; and second outgoing-side tape pull-out guide device (1, 24, 25, 26, 52) for forming an outgoing-side portion of the tape running path between the tape outgoing side of the rotating cylinder (18) and the tape cassette (11) in cooperation with the first outgoing-side tape pull-out guide device, the second outgoing-side tape pull-out guide device having a second inclined tape guide (25) always located outside the tape cassette (11) to engage with a magnetic surface side of the magnetic tape (14) running from the first inclined tape guide (23) to return the running direction of the tape (14) to the height of the tape cassette (11).