This paper presents some specific features of modern slavery. Very important changes occurred during last years. Trafficking in women and children in aim of sexual exploitation is not so dominant aspect of human trafficking. The number of committed offences of human trafficking in aim of forced labour is increased very fast. This in obviously economic crime now. In some areas of the world the most important sectors of economy depend on forced labour. Examples could be cotton production in Uzbekistan and cocoa in Ivory Coast. Some new tools as Internet create new dangers but also new possibilities to protect citizens. Some states, as the UK, adopts completely new types of regulations to prevent this criminal activity. Poland is the country of origin and destination of victims and also transit country. Comparison to other European countries gives surprising results. Per cent of slaves in Poland is third highest in our continent. One of the reasons of such situation is high number of Ukrainians looking for a job here. This nationality is the most frequently victims of forced labour in Poland. Authorities of many countries have the same problem to solve. How to find a good compromise between need for international, as strong as possible, harmonisation of standards of criminal responsibility and creation of efficient rules of law in internal aspect. At present international obligations are probably stronger and countries adopt new provision, very often just directly translating parts of international agreement as part of internal statute. The latest history of Polish regulations regarding human trafficking is good example of such practice.