Résumé
<p><b>OBJECTIVE</b>To understand the demography changes and behaviors in drug users.</p><p><b>METHOD</b>Self-reported questionnaires was used and longitudinal investigation was conducted in one of the detoxication centers in Beijing in 1998 and 2000. Drug users were randomly chosen.</p><p><b>RESULTS</b>Results showed that age of drug users tend to become younger with the numbers of drug users aged below 25, increased from 18.7% in 1998 to 28.2% in 2000. Majority of drug users remained males, but the proportion of females seemed to increase. Distribution of occupation showed that the largest increase fell among individual enterprisers, from 15.2% in 1998 to 25.9% in 2000. With educational back-ground, the proportion of lower than elementary education level, including illiterate, increased. Fifty percent of drug users were unmarried which increased from 40.8% in 1998 to 53.2% in 2000. Needle sharing was quite common, 16.5% in 1998 and 11.9% in 2000, but the decrease was not statistically significant (P > 0.05). Fifty-seven point three percent of the injecting drug users did not have constant partners to share equipments. Proportion of extra-marriage sexual practice increased from 12.5% in 1998 to 27.5% in 2000, and significant difference (Chi-square = 12.50, P < 0.001). Multiple partners in extra-married drug users was also found (mean = 2). Compared to 1998, condom use during every sexual practice increased in 2000, but 47.7% drug users still never used condom.</p><p><b>CONCLUSION</b>In summary, as the quick increase of drug users, sharing of injecting equipment and high-risk sexual behavior, including multiple partners and unprotected sex, were quite common, with the possibility of HIV epidemic in drug users.</p>