The purpose of this study is to examine lower characters in Measure for Measure, emphasizing on Pompey and Barnardine. The one is a tapster and pimp working for Mistress Overdone, and the other is a dissolute murderer in prison. In the constable Elbow’s trial scene in Act II, scene i, Pompey shows himself up using his nimble word-play in front of the deputy Angelo and Escalus, and develops a full-scale burlesque of legal procedure by building on a parody of Elbow’s malapropism. Under the deputy Angelo’s regime, however, Pompey is imprisoned for his illegal business along with a number of his old customers of the bawd house. And there, he continues his job not as a bawd but as an assistant of the Executioner, Abhorson. He bridges the theme of fornication into the theme of the heavy crime, murder. Pompey is indeed a representative figure for the ancient profession, prostitute where the line between legal and illegal remains notoriously uncertain. Barnardine, a dissolute prisoner is drunken all day long in his prison cell. When he first appears in the prison scene, Act IV, scene iii, his drunkenness dominates the stage ignoring the warrant. Pompey and Abhorson give up to take a next step, and even the disguised Duke can’t help doing anything against him. His refusal to die exposes the gap between the Duke’s bizzare plotting and the actual world. As a murderer, Barnardine is the representative antithesis of the world of comedy that emphasizes preserving and continuing human life. Sparing him from death sentence, therefore, means that he is free to kill people again. On his second appearance in the final act, he keeps silence when the Duke saved his life. Therefore, the meaning and effect of his silence is wide open to the audience and readers as well as the director. In particular, since the quantity of his dialogue is no less than 17 lines, and his appearance is limited, he used to be omitted during the last scene by some directors. If we remind the Angelo’s justice, which put the same weight on the fornication and the murder, Barnardine is the one of the most important figures who takes one opposite of the measure of this play. The lower characters in Measure for Measure, are critical mirror in which inverted the structure and assumptions central to the play’s serious action. If their roles were reduced or omitted, therefore, the whole theme of this play would be deformed and its message would be distorted. Even they are indeed minor characters, the function and the effect of their portions are as significant as major characters.