A multi-shaft transmission is mounted on a work vehicle for performing loader work, and includes a power transmission mechanism for transmitting power from an input shaft through a countershaft to an output shaft. A shifting part shifts a drivetrain from the input shaft to the output shaft. The power transmission mechanism includes a forward clutch and a reverse clutch for forward-reverse shifting, and a plurality of speed stage shifting clutches for changing speed stages, wherein at least one of the forward clutch and the reverse clutch has a plurality of speed region shifting clutches. The shifting part shifts only one clutch among the plurality of speed stage shifting clutches and the plurality of speed region shifting clutches to change speeds when a plurality of speed stages are used in be loader work.