Abstract: Compared studies between the pharmacokinetics of phenylpropanolamine(PPA)controlled release suspension ( CRS ) and that of PPA conventional tablet in l0 healthy volunteers showed that the maximal plasma concentration(C_max), the minimal plasma concentration(C_min)and the fluctuation index (FI) values were 169. 06±7. 76 ng· ml^-1, 82. 80±4; 29 ng· ml^-1and 0. 20 ±0. 04 respectively for PPA CRS, 180. 05±8. 91 ng· ml^-1, 76. 18±5. 97 ng·ml^-1and 0.81±0.07 respectively for the conventional tablet. The Cnaxand FI of PPA CRS were significantly lower compared with those of the conventional tablet(P<0. 01 ) during steady state, The C_min of PPA CRS was higher than that of the conventional tablet(P<0. 05)。