1. Draft and submit a complaint to demand the child's father or mother to pay alimony;

2. Submit a complaint to the court of the other party's domicile and pay the filing fee 20 yuan;

3. Waiting for the court to arrange a hearing;

4. Prepare relevant evidence before the trial, such as divorce agreement or judgment;

5. The fees for accepting a case shall be paid cumulatively by stages according to the amount or price requested by the lawsuit, and the fees have different proportional standards according to different amount ranges of property cases.

Composition of support for children born out of wedlock;

1, basic living expenses: used to meet the basic needs of children's daily life, such as food, clothing, housing and transportation;

2. Education expenses: including tuition, books and other education-related expenses in preschool education, compulsory education, high school and university education;

3. Medical expenses: covering children's routine physical examination, treatment expenses and necessary medical insurance premiums;

4. Special needs expenses: used for children's special needs, such as rehabilitation expenses or special education expenses for disabled children;

5. Other expenses: Other expenses that may occur according to the child's actual situation, such as interest class expenses and living AIDS.

To sum up, the process of suing illegitimate children for alimony includes drafting a complaint, submitting it to the court and paying the filing fee, waiting for the court session, preparing relevant evidence, and paying the case acceptance fee according to the amount of litigation, in which the case acceptance fee is paid cumulatively according to different proportions of the amount of property cases.

Legal basis:

People's Republic of China (PRC) Civil Code

Article 107 1

Children born out of wedlock enjoy the same rights as children born in wedlock, and no organization or individual may harm or discriminate against them. The biological father or mother who does not directly raise children born out of wedlock shall bear the responsibility for raising minor children or adult children who cannot live independently.

People's Republic of China (PRC) Civil Procedure Law

Article 119

The prosecution must meet the following conditions: (1) the plaintiff is a citizen, legal person and other organization that has a direct interest in the case; (2) Having a clear defendant; (3) Having specific requests, facts and reasons; (4) It falls within the scope of civil litigation accepted by the people's court and is under the jurisdiction of the sued people's court.

Article 109

The prosecution shall submit a complaint to the people's court, and submit copies according to the number of defendants. If it is really difficult to write a complaint, it can be made orally, which will be recorded by the people's court and the other party will be informed.

Article 110

The complaint shall contain the following items:

1. The name, sex, age, nationality, occupation, work unit and domicile of the party concerned, the name and domicile of the legal person or other organization, and the name and position of the legal representative or principal responsible person;

2. The request and the facts and reasons on which it is based;

3. Evidence and sources of evidence, names and residences of witnesses.