TJ-1 volumetric strainmeters, developed by Su Kaizhi (Seismogeological Brigade, State Seismological Bureau) and others, installed in Xuzhou (徐州), Wenquan (温泉) and Fengfeng (峰峰), had yielded the first set of observational data. Venedikov's harmonic analysis for these data were made and some preliminary results were obtained. The results indicated that TJ-1 volumetric strainmeter could record comparatively authentically the earth strain tide and in a good state their precision could reach 5×10-9 (mean square-...