For the effective measurement of the reopening pressure in hydraulic fracturing, it is necessary to use the testing equipment with sufficiently small compliance. If not, there is no way to estimate the maximum stress in a plane perpendicular to a borehole, i.e. the maximum horizontal stress assuming a vertical borehole, from the reopening pressure. It may be very hard to reduce the system compliance drastically by just replacing any components of the hydraulic fracturing system. If the flow meter is emplaced as close as possible to a test section of a borehole isolated by straddle packers, the system compliance can be reduced drastically. To accomplish this idea, we have been developing a testing system with a downhole flow meter.We demonstrated the developed system in a field test successfully. Furthermore, we presented a new method which will allow us to do stress measurement at depths greater than a few km.