Total juvenile arrests under 15 years of age increased from 307,584 in 1963 to 526,421 in 1988, but the figure for juvenile arrests as a percentage of all arrests declined from 6.6 to 5.2 percent over the same period. Total juvenile arrests under 18 years of age increased from 788,762 to 1,725,746, while the percentage of juvenile arrests as a percentage of all arrests decreased from 17.5 to 16.1 percent. Two major problems in using arrest statistics are identified: (1) they are incorrect due to human error in tabulating and reporting to the UCR system; and (2) they do not reflect changes in police operational practices, such as handling more juveniles informally without arrest. The Youth Crime Index is considered to be a more realistic way of assessing juvenile crime, as opposed to arrest statistics. This index indicates that the intensity of juvenile crime continues to increase. 14 references and 5 tables