Acetaminophen, fenbufen, and mefenamic acid tablets were formulated with the same additives, granulated to different sizes, ranging $30{sim}200mesh$, and compressed by pressure of $0.5{sim}2.0;ton{cdot}cm^{-2}$. The hardness and disintegration time of the three tablets were determined. The dissolution rates of the three tablets at critical point of pressure were investigated. The results showed that fenbufen, and mefenamic acid tablet had critical compression pressure of $1.0;ton{cdot}cm^{-2}$, but acetaminophen tablet had that of $1.5;ton{cdot}cm^{-2}$. Neverthless, three tablets were disintegrated within 5 min. Among the three tablets, mefenamic acid tablet followed zero order of dissolution and the rate constants were as fellows; $1.68 ;mg{cdot}min^{-1};(30{sim}50mesh),;1.76mg{cdot} min^{-1};(50{sim}80;mesh);and;4.85;mg{cdot}min^{-1};(80{sim}200mesh)$.