Abstract: Objective To evaluate the performance of the early detection of HIV infection and related factors in Xiacheng district of Hangzhou, Zhejaing province and provide evidence for the early detection and early treatment of HIV infection. Methods Follow up was conducted for newly detected HIV positive persons to detect their CD4 T lymphocyte regularly, determine the interval between the first HIV positive detection and the first detection of CD4 T lymphocyte and analyze the first change of CD4 T lymphocyte count. Univariate and multivariate logistic regression analyses were conducted to identify the influencing factors for the early detection of HIV infection. Results During 2009-2013, a total of 738 new HIV infection cases were detected, in which 663 (89.8%) were tested for CD4 T lymphocyte and the cases whose CD4 T lymphocyte was first detected within 1 month, after 1 month, after 3 months and after 1 year accounted for 58.4%, 27.9%, 11.6% and 2.1% respectively. There was no statistical significant differences in the annual detection of low CD4 T lymphocyte count (P0.05). Logistic regression analysis indicated that the influencing factors for the early detection of HIV infection included age, marriage, residence, education level, testing institution, exposure history and sample source, the difference was statistical significant (P0.05). It is difficult to conduct early detection of HIV infection by testing the married, divorced or widowed and others, through preoperative detection and through positive spouse/sex partner detection. The odds ratio were 0.494 (95% CI: 0.286-0.853), 0.609 (95% CI: 0.374-0.994), 0.251 (95% CI: 0.143-0.440), 0.346 (95% CI: 0.177-0.675) and 0.318 (95% CI:0.109-0.928), respectively. Conclusion The early detection of HIV infection in Xiacheng district is performed well. Strengthening the counsel and test for HIV among the unmarried would facilitate the early detection of HIV infection.