The G gamma:A gamma ratios of Hb F were determined in 331 newborn babies of the Man ethnic group in Liaoning Province, P.R. China, using polyacrylamide gel electrophoresis; in 27 cases they were also determined by reversed phase high performance liquid chromatography. The results showed that a high G gamma value (> 80%) was present in four cases (1.21%) and low G gamma values (30-48%) in six cases (1.81%); not a single case with the A gamma T [A gamma 75(E19)Ile->Thr] chain was found. Gene mapping analysis demonstrated that two babies with high G gamma values had the -G gamma-G gamma-/-G gamma-A gamma- (0.60%), and two others the -G gamma-AG gamma-A gamma-/-G gamma-A gamma- (0.60%) arrangements. Two of the four babies with low G gamma values were identified as -A gamma-A gamma-/-G gamma-A gamma- (0.60%) and the other two as -GA gamma-/-G gamma-A gamma- (0.60%). The genotype -A gamma-A gamma- has not been reported before in Chinese.