Legal analysis: It is a necessary measure for employers to train specific workers in professional operation skills and professional knowledge to meet the needs of special posts. As long as the employer provides workers with special training fees and carries out professional skills training, the service period can be agreed. According to the provisions of relevant laws, if a worker violates the service period agreement, he shall pay liquidated damages to the employer as agreed.

Legal basis: Article 22 of People's Republic of China (PRC) Labor Contract Law. Where an employer provides special training fees for laborers and provides them with professional and technical training, it may conclude an agreement with the laborers to stipulate the service period. If the laborer violates the service period agreement, he shall pay liquidated damages to the employer in accordance with the agreement. The amount of liquidated damages shall not exceed the training expenses provided by the employer. The liquidated damages that the employer requires the laborer to pay shall not exceed the training expenses that should be shared for the unfinished part of the service period. If the employer and the employee agree on the service period, it will not affect the employee's improvement of labor remuneration in accordance with the normal wage adjustment mechanism during the service period.