Objective: The previous studies showed that scaffold structure especially microstructure may be an important factor for osteoinduction.In this study, hydroxyapatite micropores were produced by using graphite powder as porogen and to detect scaffold micropores effect on osteoinduction in vitro.Methods: Micropore size was precisely control by using graphite powder as porogen.When graphite powder sintered with HA, it reacted with oxygen and evaporated as CO2, so two kinds of HA discs with different micropores (HA1 and HA5) and one kind of dense HA (HA0) discs were created.MG63 cells were used to study the effect of HA micropore on the response of cultured cells.