Objective To measure the body weight and body size of the F1 generation in Rongshui miniature pig (RMP). Methods 83 F1 generations of RMPs (48 females and 35 males) were selected randomly. 9 traits included body-weight, body-length, body-height, chest-circumference, chest-breadth, chest-depth, circum of pastern, girth of leg and rictus were measured, and analyzed statistically by SPSS statistical software and Logistic nonlinear growth analysis model. Results In the F1 generations of RMP, the weights of birth day、6^thmonth and 12^th month of female and male were 0.61±0.14 kg and 0.55±0.13 kg, 17.21±5.20 kg and 16.35±5.23 kg, 26.97±6.49 kg and 26.53±5.65 kg respectively. There was no difference significantly between the genders of the 9 measured traits except for born-weight, born-length and chest-breadth in 10^th month (P < 0.05). According to the analysis in Logistic model, body-weight inflection point was between 5^th-6^thmonth, body length and girth of leg inflection points were 2^nd～3^thmonth, while inflection points of other traits were 1^st～2^nd month. Conclusion The F1 generations of RMP showed low mature body weight and sweet temper. It should be breed as good laboratory miniature pig.