The present study was designated to know the sero-prevalence status of H9 antibodies in Sonali chickens at Joypurhat district in Bangladesh by initial screening of AIV type A by ELISA followed by H9 LPAI detection by HI test. 180 sera samples from 18 flocks were collected and screened for Avian Influenza Virus type A antibodies by ELISA. All ELISA positive samples were tested by HI test, specific for H9 antibodies. On ELISA, sero-prevalence for AIV type A were 14.4% and 3.3% in older aged group (≥11weeks) and growing aged group (≤10 weeks) respectively, with an overall sero-prevalence of 8.89% in Sonali chickens at Joypurhat district. Among these AIV sero-positive samples, 92.31% 0f older aged group and 66.67% of growing aged group chickens found sero- positive to H9 antibodies by HI test with an overall 87.5%. Out of 180 sera samples, only 14 samples found positive to H9 antibodies, indicating 7.78% sero-prevalence in Sonali chickens of Joypurhat district. This study revealed higher sero-prevalence of AIV antibodies as well as H9 antibodies in older aged group which might be due long-time exposure to infections. Sero- prevalence of both AIV type A and H9 LPAI are higher in older aged Sonali chickens. The findings of the present study suggest that the overall seroprevalence of AIV type A and H9 LPAI in Sonali chickens are 8.89% and &.78% respectively, at Joypurhat district in Bangladesh and also suggest that H9LPAI virus in circulation in Sonali chickens at Joypurhat district in Bangladesh.