In present changeable environment of running the company, the planning process including especially cost planning has a special meaning. No company may allow to improvise that's way a rational system of cost planning should be developed. To offer the competitive prices the company must be able to determine precisely a products cost. For the cost planning system labour costs play an important role. They include all expenses covered by an employer and concerned with people involved in business activity. Developed Structure of the labour cost consists of different elements, such as wages and salaries, costs of insurance rates, social charges, training and personnel development costs, costs of ensuring work hygiene and safety and others. The knowledge of the labour costs is important for their rationalisation and optimisation from viewpoint of quantitative and qualitative employment Structure due to company's development strategy. The account and analysis of the labour costs provide the basis for making many managerial decisions. The study of the labour cost aims at providing the managers with the detailed data about expenses carried on labour and making appropriate decision on better and effective use of human resources. The major part of the labour costs is compensation, which consists of many components. Among them the more important is the basic pay. To be motivating and objective it should be determinant of the job content; that means job's requirements. All this is taken into account during the process of job evaluation. The basic pay is usually supported by variable payment components such as bonuses or rewards, which should be implemented to the company's remuneration system in proper way. The properly designed bonus system should be concerned with results obtained by company as a whole, next with results obtained by particular departments or teams and finally with achievements of particular employees. Rationalization of labour costs Structure aims at seeking the rational links between expenditure for labour and results of work within workplace, group of workplaces, department as well as whole organisation. To compare labour costs on particular workplaces and to forecast changes in labour costs, the knowledge about basic rates, other remuneration components and material environment is needed. This knowledge is provided by well prepared, implemented and maintained job evaluation and pay differentiation system. From viewpoint of production process planning and control it's very important to know how many and what kind of employees are required in a given period. Knowing the ąuantity and quality of needed resources we can estimate the time of order completion as well as the labour costs related to employees involved in the manufacturing processes. The problem of human resources planning is complex because human factor is the most unforeseeable. It is very difficult to foresee future human behaviour, absenteeism. Additionally, the labour law introduces many limitations related to way and time of human resources use.