Abstract: Background and Objective: The growing population number combined with limited food resources resulted in the great need for alternative protein sources and functional food. This study aimed to prepare functional labenah using edible green algae, Spirulina platensis, as a rich source of protein and enhancer of Bifidobacterium activity. Materials and Methods: This study was divided into two parts. The first one, was to study the effect of different concentrations of Spirulina platensis (1, 3 and 5 mg mL–1 pure media) on the activity of Bifidobacterium. The second was to study the properties of three different labenah samples; the first one used as control (T1) and contained 2% traditional yogurt starter culture. The second (T2) was prepared by adding 2% Bifidobacterium spp. The third treatment (T3) contained 5 mg mL–1 of Spirulina platensis powder plus 2% Bifidobacterium spp. All labenah samples stored at 5°C for 21 days and analyzed when fresh and after 7, 14 and 21 days for acidity percent; pH values and TVFAs contents. Color parameters and sensorial properties were also estimated during the same periods of storage. Results: Supplementation of Spirulina platensis markedly activated the growth of Bifidobacterium spp. While, slight differences were observed in the studied chemical parameters of the three different labenah samples. Obtained data revealed that the acidity percent of samples as well as TVFAs contents were slightly increased in treated samples rather than control and in stored samples rather than fresh. The pH values took an opposite trend. Noticeable and clear differences between control and treated samples were observed in color parameters and sensorial evaluation. Results also indicated that using of Spirulina platensis gave a clean and moderate acid taste with an acceptable color and favorite properties. Conclusion: Using 5 mg mL–1 of Spirulina platensis powder succeeded in preparing acceptable labenah samples and promote the growth of Bifidobacterium. So it is recommended to use this formulation to prepare labenah. Further studies should be done in food sector to prepare another algal dairy products using Spirulina platensis powder.