To provide a method for producing a modified acrylic resin having the less amount of odor-generation by a simple method not newly connecting an extruder exclusive for deodorization nor requiring a highly expensive deodorization facility.

This method for producing the modified acrylic resin by performing the modification reaction with the extruder is provided by using the extruder having a feeding zone, a reaction zone 2 and an odor-eliminating zone 3, and having a L/D of 5 to 20 in the odor-eliminating zone 3. By the method for producing the modified acrylic resin, it is possible to eliminate an odor material in the resin and produce the resin without having thermal deterioration.