This research will begin with the statement that a relationship between two individual always passes through different phases. Rob Reiner's romantic comedy When Harry Met Sally is a movie which gives an idea about how a relationship can grow between two strangers, what are the different phases their relationship can pass through and what are the common characteristics that a relationship can have. When Harry Met Sally is a romantic movie directed by Rob Reiner, released in 1989. The main two characters of the movie Harry and Sally were played by Billy Crystal and Meg Ryan. The movie begins with two unfamiliar persons Harry and Sally, newly graduated from the University of Chicago jointly travel in a car from Chicago to New York, a place where they would find their living. In this movie, for a period of 11 years, during the basic stage of their relationship, both Harry and Sally debated about a common fact and that was can a man and women be a non-sexual friend or not. If we analyze both the characters, Harry give the impression of carefree attitude, but is doubtful enough to “read the last page of a book first”; in case he dies, he says, “at least he'll know how it ends. And know-it-all Sally insists that Ingrid Bergman really wanted to leave Humphrey Bogart. From the dialogue of Sally, ''I don't want to spend the rest of my life in Casablanca with a guy who owns a bar” her attitude towards life becomes very clear and also clearly represents who she is at that point of time. It presents the story of ten years down the line when Sally had a break up with her boyfriend and Harry’s wife left him and they again become best friends. Mark Knapp's 10 stages of Relational Development and the movie Harry Met Sally: To analyze the relationship development, Mark Knapp discussed10 different stages associated with it. Adler and Rodman in their book discussed all these stages. Although it is not an interpersonal theory still according to his concept the ten stages of an interpersonal relationship are “Initiating, Experimenting, Intensifying, Integrating, Bonding, Differentiating, Circumscribing, Stagnating, Avoiding, and finally Terminating”. If one analyzes the movie When Harry Met Sally, it is very clear that relationship development not always follow Knapp’s 10 stage of development. If we analyze the movie then it is clear that out of first five stage of relationship development initiating was started when they first meet, then they were trying to find out whether a friendship among boys and girl can happen without any sexual relation, that is the experimenting phase. Later on, their friendship intensifies but it was split asunder after a spur-of-the-moment night of passion when she was upset about an ex-marrying someone else. The flow of the movie also resembles the way Adler and Rodman mentioned in their book about the flow of stages of relationship development among them. Their relationships have the stages of initiation, then integration of their thought process, and then they slowly started to like each other as their bonding grew. The main thought process which they were thinking about was related to whether friendship only related to sex or not. As they started to get involved in own personal life, slowly their interaction decreases, as mentioned by Adler and Rodman, it was the circumscribing stage. This was followed by avoiding. But when in their own life both of them separated from their partners they meet again, and during that time they do not have the necessity to start the relationship from the first stage again. Another key point associated with this movie is the self-disclosure. Self-disclosure is a key part of the integrating stage of the relationship development. When any couple reaches the integrating stage they are already very close to one another.