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<p>Hydroperoxide esters, formed in the reactions of carbonyl oxides (also called Criegee intermediates, CIs) with formic acid, play a crucial role in the formation of secondary organic aerosol (SOA) in the atmosphere. However, the transformation mechanism of hydroperoxide esters in the presence of stabilized Criegee intermediates (SCIs) is not well understood. Herein, the oligomerization reaction mechanisms and kinetics of distinct SCI (CH<span class="inline-formula">₂</span>OO, <i>syn</i>-CH<span class="inline-formula">₃</span>CHOO, <i>anti</i>-CH<span class="inline-formula">₃</span>CHOO, and (CH<span class="inline-formula">₃</span>)<span class="inline-formula">₂</span>COO) reactions, with their respective hydroperoxide esters and with hydroperoxymethyl formate (HPMF), are investigated in the gas phase using quantum chemical and kinetics modeling methods. The calculations show that the addition reactions of SCIs with hydroperoxide esters proceed through successive insertion of SCIs into hydroperoxide ester to form oligomers that involve SCIs as the repeated chain unit. The saturated vapor pressure and saturated concentration of the formed oligomers decrease monotonically as the number of SCIs is increased. The exothermicity of oligomerization reactions decreases significantly when the number of methyl substituents increases, and the exothermicity of <i>anti</i>-methyl substituted carbonyl oxides is obviously higher than that of <i>syn</i>-methyl substituted carbonyl oxides. The <span class="inline-formula">−</span>OOH insertion reaction is energetically more feasible than the <span class="inline-formula">−</span>CH insertion pathway in the SCI oligomerization reactions, and the barrier heights increase with increasing the number of SCIs added to the oligomer, except for <i>syn</i>-CH<span class="inline-formula">₃</span>CHOO. For the reactions of distinct SCIs with HPMF, the barrier of the <span class="inline-formula">−</span>OOH insertion pathway shows a dramatic decrease when a methyl substituent occurs at the <i>anti</i>-position, while it reveals a significant increase when a methyl group is introduced at the <i>syn</i>-position and dimethyl substituent. Compared with the rate coefficients of the CH<span class="inline-formula">₂</span>OO <span class="inline-formula">+</span> HPMF reaction, the rate coefficients increase by about 1 order of magnitude when a methyl substituent occurs at the <i>anti</i>-position, whereas the rate coefficients decrease by 1–2 orders of magnitude when a methyl group is introduced at the <i>syn</i>-position. These new findings advance our current understanding of the influence of Criegee chemistry on the formation and growth processes and the chemical compositions of SOA.</p>