Radionuclide gastric emptying studies, including solid and liquid phases, were used to evaluate the gastric motility of healthy Chinese. Forty-eight patients (18-76 years old) and 38 volunteers (27-79 years old) accepted solid or liquid food gastric emptying studies, respectively. The solid meal was two fried eggs mixed with 500 microCi Tc-99m phytate and two pieces of toast to form a sandwich. The liquid meal was 500 ml of water with 5% glucose and 500 microCi Tc-99m phytate. Studies were performed with the subjects in the supine position and a gamma camera in a left anterior oblique (LAO) position while data were collected for 90 minutes and 30 minutes after finishing the solid and liquid meal, respectively. The gastric emptying time was presented as a half-time (t1/2) of the food emptying from the stomach. The study results showed that the t1/2 is 89.0 +/- 17.8 in older patients (> 60 years old) and 88.0 +/- 18.2 in younger patients (< or = 60 years old) for the solid phase studies (P > 0.05), and that the t1/2 is 46.2 +/- 11.1 in older patients (> 60 years old) and 31.9 +/- 11.3 in younger patients (< or = 60 years old) for the liquid phase studies (P < 0.05). We concluded that the age effects of gastric emptying in healthy Chinese occurred only in the liquid phase.