Abstract: Objective To analyze the management and its effectiveness in close contacts of COVID-19 in Guangzhou City. Methods General demographic information, relationship and contact situation with related cases, and medical observation outcome of close contacts were collected to compare the above characteristics of close contacts in 1^st（from January 21-30）, 2^nd （from January 31 to February 8）and 3^rd （from February 9 to March 2）period. Results A total of 2 312 close contacts were tracked. Male-to-female ratio was 1.15∶1, most of them were 20-59 years old, accounting for 73.53%. Isolation rate was 96.63%, close contact to case ratio was 8.59, positive rate of close contact was 5.49%, proportion of case was 35.28%. Median time of last contact to oncome, oncome to diagnosis were 2 d and 4 d, respectively. From 1^st to 3^rd period, isolation rate （ from 91.88% to 97.83%, P<0.01） and close contact to case ratio （ from 3.86 to 41.26, P<0.01） increased, positive rate of close contact （from 14.06% to 1.13%, P<0.01） decreased, proportion of case （ from 23.94% to 54.00%, P<0.01） increased, median time of oncome to diagnosis （ from 4 d to 0 d, P<0.01） decreased. Close contacts with social contact related （from 16.24% to 42.63%, P<0.01）, general or occasionally contact frequency （from 42.57% to 90.64%, P<0.01） increased. Compared with negative group, positive group had a shorter time of last contact to observe in whole period and 3^rd period （P<0.01）. Conclusion COVID-19 has been well controlled from community epidemic by sequential strengthen and effective management of close contacts in Guangzhou City. We suggest to establish a classification scheme for close contact management of different infection risk, so as to precise prevention and control.

Key words: COVID-19, Close contact, Management, Effectiveness