Purpose: Though improvement in the efficiency of ultrasound treatment is expected in combination with microbubbles, because microbubbles disperse in the bloodstream, we have attempted to actively control microbubbles in blood flow by means of acoustic radiation force in order to increase the local concentration of the microbubbles. Bubble liposomes (BLs), which have a high potential to contain various kinds of drugs, are ready for in vivo applications, and investigation of the possibility of active control is needed. However, the controllability of microbubbles in blood flow has not been confirmed. Because the average diameter of BLs is 0.5 μm, their concentration cannot be measured with conventional optical observation. Subjects and Methods: Therefore, we established a method for identifying the concentration of BLs from the brightness variations in ultrasound images (echograms) with two kinds of suspension, i.e., normal saline and porcine blood. First, we derived an acceptable mechanical index at which the effect of BL destruction can be ignored when measuring the concentration. We then examined the active path selection of BLs using a Y-form bifurcation of artificial blood vessels with focused ultrasound with a central frequency of 5 MHz and a maximum sound pressure of 300 kPa-pp, in a flow velocity of 30 mm/s. Results and Discussion: The experiments confirmed less destruction of BLs with the medium of porcine blood as compared with normal saline. Furthermore, higher induction performance was confirmed when the focal point of ultrasound emission was several mm away from the bifurcation point versus the focal point corresponding to the bifurcation point. Conclusion: From these results there is a possibility to enhance the controllability of in vivo BLs.