From May to December 2009, the department of clinical microbiology at Danang hospital in collaboration with NK-Biotekfirm had analyzed in 149 chronic hepatitis B patients in Da Nang for HBV genotype, mutations that was resistant to lamivudine and adefovir and mutations in precorelcore promoter region of HBV genome with direct sequencing method. The prevalence of men and women was 97/149 (65 percent) and 52/149 (35 percent), the mean age of population study was 30.9 + or -10.4 years. And 113 (85.8 percent) patients had a positive test for HBeAg (HBeAh[+]) and 36(14.2 percent) with negative test for HBeAg (HBeAg[-]). Results: HBV genotype B and genotype C were detected in 126 patients (84.4 percent) and 23 patients (15.7 percent), respectively. Mutations that were resistant to lamivudine were found in 19 (12.9 percent) patients including M204I (21.1 percent), L180M/M204V (42.1 percent), M204I/L80I or V207M (21.0 percent). In 36 patients with HBeAg [-], 19/36 (52.8 percent) had been detected mutations in pre-corelcore promoter region, of those 13/36 (36.1 percent) patients with precore mutant and 6/36 (16.7 percent) patients with core promoter mutations and 2/36 (5.6 percent) had mutations in both pre-core and core promoter region.