Hard capsules filling machines are useful for some reasons: with them we can quick pack small quantities of powder, can make drugs for clinical trials, also can use them for students learning in university. But in literature we couldn’t find method how to count the right quantity of powder, need to fill in one capsule. For this reason, we perform some experimental works with acetylsalicylic acid, paracetamol and lactose to find out how it does right. During these works, we research how affect powder flow, powders moisture, filling condition, powder particle size to the capsules filling. Also we research is any differences between capsules position in capsules filling machine and its weight. To find is our method right, we made 3 series of acetylsalicylic acid capsules and made uniformity of content and uniformity of mass tests with them. Made accomplished fulfils European pharmacopeia’s demands.