Hey Friends

I would like to watch a drama where Female Lead is forced to get married to Emperor. And at first Emperor is also not interested in her but with the time he falls in love with her. I want her not to fall in love with Emperor. Generally I see dramas where Female Lead Loves Emperor even though he has a number of concubines. I don't want her to fall in love with Emperor. And the story should be a serious one.

This is a hard one. 

Try Legend of Concubine Zhen Huan. I think it’s the closest to what you are looking for. 

Maybe legend of Mi yue 

Story of Yanxi palace maybe. 

Reverse harem dramas where an Emperor (or two) falls in love with the FL, one way or another the FL becomes pregnant with the Emperor's child, and in the end the FL chooses to leave the palace:

  • The Imperial Doctress - The ML (Emperor) and the SML (his brother) both fall for the FL, although the ML tries to deny his feelings, mainly because he is already married. The SML courts the FL. Although she likes him, I wouldn't say she falls in love with him, but he manages to convince her to agree to marry him. Then through a series of events the ML and the FL become prisoners of war. The SML takes over as Emperor and marries someone else to secure his position. When the FL and ML return to the capital, the ML and FL each make sacrifices to help one another, while the SML takes the FL as his concubine and rapes her, which results in her becoming pregnant. Ultimately the FL leaves the palace to practice medicine (what she's always wanted to do) and the ML returns to his position as Emperor until his son is old enough to take the throne. Then the ML leaves the palace to meet the FL again.
  • Moon Lovers: Scarlet Heart Ryeo - The FL (Ha Jin) is a girl from the present whose spirit travels to the past and enters the body of a noble woman (Hae Soo), who is a cousin of a woman who is the ailing wife of the SML, one of several princes. The FL and SML fall for one another despite the fact that the SML is married and his wife is dying. The ML, another prince, also falls for the FL despite initially acting prickly towards her (that's how he acts towards everyone). As a result of Hae Soo's family's actions, the FL is almost forced to marry the Emperor (father of the ML and SML - he doesn't have romantic feelings for her), but she takes steps (which have steep consequences) to avoid the marriage. The SML betrays the FL and she gets over her feelings for him. She later falls for the ML and their relationship becomes one where they sleep together. The ML becomes Emperor but decides not to marry the FL for political reasons and marries a different woman to secure his position. The FL chooses to leave the palace and the ML due to the ML's hunger for power and ruthlessness, despite her feelings for him and the fact that she is pregnant with his child. She marries the ML's brother (not the SML) who loves her but who she views as a friend, and dies as a result of illness in her husband's manor shortly after giving birth.

Reverse harem dramas where a character who becomes Emperor falls for the FL and she does not return his feelings:

  • The Princess Wei Young - The ML is a prince who is the Emperor's grandson and the son of the former crown prince (now deceased). The SML is the prince's uncle and both are potential future Emperors. The ML falls for the FL right away. The SML is not interested in the FL at first, but later falls for her. That doesn't stop him from having an ongoing sexual relationship with another girl who is sort of related to the FL and hates her. The SML plans a coup where he takes over as Emperor, takes the ML prisoner, and forces the FL to agree to marry him (she pretends to agree for the sake of a long term plan to overthrow him on their wedding day). The FL never falls in love with the SML. Ultimately the ML and FL defeat the SML and the ML becomes Emperor for a few years. When he dies, the FL takes over as Empress. 
  • Dreaming Back to the Qing Dynasty - The FL in this one isn't the brightest FL ever. She is essentially haunted in modern times by the spirit of the ML, a prince from the past, and they fall in love. The FL then travels back in time and meets the ML, but then a mystical event causes both of them to forget each other. The FL becomes confused and thinks that the man that she fell in love with and is looking for is the SML (the ML's brother). Overall the ML (who is not married) and two of his brothers (who are both potential future Emperors and both marry or are already married to other women) have all fallen for the FL. The FL later realizes her error, falls for the ML, and marries him. She makes it clear to the SML that she does not return his romantic feelings. The SML later becomes Emperor.