Ray Bolger was supposed to play the Tinkerman at first, but he insisted on playing the Scarecrow because his idol Fred Stone played the Scarecrow on the stage in 1902, and Buddy Ebson was the first person to play the Scarecrow. Had to switch, but Ebson had an allergic reaction to the aluminum powder used by the Xipi people and had to give up the performance; later, the role of the Xipi people was replaced by Jack Haley.
Originally, the producer planned to dress the witch as a coquettish and beautiful woman, so the producer Melvin Leroy invited MGM actor Gail Sandgard to play the witch, but the appearance of this sexy witch made the story. There are loopholes in the plot. In desperation, the image of the witch must be changed to be ugly, and Sandgard, who found himself totally unrecognizable, refused to play this role. Eventually Margaret Hamilton succeeded Sandgard as the witch.
The film studio originally planned to let Shirley Temple play Dorothy, but because Shirley Temple signed the 20th Century Fox and MGM incompatibility, Shirley Temple lost this opportunity, so it changed Dorothy is played by Judy Garland.
