Abstract: To compare the early growth performance of the Sinonovacula constricta family group and colony group, we chose the excellent group from Leqing Bay to conduct the growth experiment. We established a selection group and 27 full-sib families(F₁、F₂...F₃₀), because of the high mortality rate, the full-sib families F₁₈, F₂₄ and F₂₈ are eliminated in the early days. For the selection group, the control group is breeding population group. For the full-sib families, single pair method is applied. And analyses were made about the fertility rate, the metamorphosis rate, the adhesive rate, the growth rate and size specification in different terms. By multiple comparison and variance analysis, it was indicated that there was no significant difference of the fertility rate, the metamorphosis rate, the size of D-type larva and the adhesive rate between different experimental groups. For all the experiment groups, the individual size and growth rate are different in different development periods. And the size and growth rate of group selection are greater than those of breeding population with significant difference. Among the full-sib families, there were also differences in the growth rate. Groups of F₂, F₇, F₉, F₁₃, F₁₉, showed greater growth vigor than the control group with significant difference. Groups of F₅, F₆, F₁₄, F₂₅, F₂₇ showed growth disadvantage compared with control group, also with significant difference. The paper conducted comprehensive comparison of early growth performance between family group and colony group, and obtained the excellent family and colony, providing basic data and excellent material for fine varieties breeding of S. constricta in the future.