The paper describes key standards of proof used in common law countries: balance of probabilities and beyond reasonable doubt,applied in judicial practice in the UK, and the criminal standard beyond reasonable doubt, civil standard preponderance of evidence,and interim standard clear and convincing evidence, applied in judicial practice in the USA.
 The author identifies main conditions for application of the balance of probabilities standard in foreign judicial practice: 1) thisstandard is not merely a surmise based on guesses or suspicions; such surmise shall be based on certain evidence, which in total is notenough to establish presence or absence of a certain fact unequivocally; 2) the graver is an allegation, the less probable is the occurrenceof the fact, and hence it must be proved with harder evidence; 3) the less probable is an event, the more evidence there must be to provethat it might have truly occurred; 4) there is no direct connection between graveness of an allegation (consequences) and probability ofan event: some grave harmful conduct may be fairly common or, on the contrary, may happen rather infrequently.The paper identifies step-by-step implementation of standards of proof in practice of the European Court of Human Rights(ECHR): at the first stage one can find references to standards of proof only in cases against the United Kingdom; at the second stagethere are judgments made on complaints against other countries, though in such judgments the ECHR does not assess standards ofproof, but merely reflects that those have been applied by national courts. At the third (contemporary) stage the ECHR only distingui -shes between application of standards of proof in criminal and quasi-criminal cases.The author concludes on the basis of study of empirical data that the balance of probabilities standard of proof is already appliedin the national judicial practice, however principles of its application in the judicial practice have not been developed yet. It is notedthat though the doctrine of the standards of proof was developed in the common law countries, application thereof does not contradictthe concept of judicial activism: an idea, according to which a decision must be made in favour of the party, whose statements are reliablenot per se, but in comparison with statements of the adverse party, enables courts to make judgments in cases when positions ofboth sides are impeccable, and evidence for unequivocal conclusions is not enough.