where can I study the course about Employment Ordinance?

HKU, CUHK or Federation of Trade Union (工聯會) have such courses tailored made for HR officers.

If you want to get information concerning the Employment Ordinance, it is best to go to the website of the Labour Department (http://www.labour.gov.hk), where you can download various publications on the Employment Ordinance or get information about the updated amendments of the Ordinance. The Labour Department is the most authorative body in Hong Kong as far as labour relations are concerned.

Although there are some trade unions which include information on the Employment Ordinance in their websites, the view points are sometimes rather biased, especially biased for the workers at the disadvantage of employers. But, it is understandable because their target groups are the workers, not the employers.