Objective: Identify Cocsackie B virus serotypes from acute flaccid paralysis patients in the Northern provinces, Vietnam for the period 2005-2007. Subjects: The strains intestinal virus (132 strains) isolated from 690 patients were monitored acute flaccid paralysis detected in 3 years, from 2005 to 2007 in the North were included in the study on the root structure and a number of distribution characteristics intestinal virus strains isolated from patients. Method: The study virology laboratory. Results: 690 samples were then inoculated on RD cell lines, 152 samples HEP2 and L20B cause cell damage, accounting for 22.0 percent rate. Proportion of virus isolation in the years from 2005-2007 is the equivalent of 24 percent, 25 percent and 16 percent respectively. The samples are then continuously determine serum Inaba (serotyp) of beneficial intestinal bacteria by neutralizing trace methods in cell and molecular biology methods. Among these serotypes identified intestinal virus 65 Echo virus samples (42.7 percent of positive samples), 20 samples Coxsackie B virus (13.2 percent), 6 Coxsackie A virus samples (3, 9 percent), 6 samples of intestinal virus type 71 (3.9 percent), Polio virus 10 samples (6.6 percent). However, up to 45 samples unidentified virus serotypes (29.6 percent). The unidentified virus samples above were analyzed further using molecular biological methods. Results Coxsackie A virus identified by neutralization methods and molecular biology have resulted serotype 8 virus type CA including 4, 6, 7, 9, 10, 16, 21 and 24. CA24 is the main of which 38 percent of strains isolated CA, and the main focus in 2006. 2006 was also the year with the ratio CA viruses isolated highest, accounting for nearly 50 percent of the total sample CA positive, while the 2005 and 2007 rates of approximately the same positive CA.