Grid-connected　voltage　source　converters　(VSCs)　have　been　broadly　applied　in　modern　power　system.　However,　instability　issues　may　be　triggered　by　the　integration　of　grid-connected　VSCs,　jeopardising　the　operation　of　the　power　grid.　Conventional　stability　analysis　methods　can　be　utilised　to　derive　system　stability　margins　under　nominal　conditions.　Whereas　grid-connected　VSCs　inevitably　operate　under　multiparameter　uncertainty,　which　may　result　in　overly　optimistic　or　even　incorrect　estimations　of　stability　margins,　thereby　posing　potential　risks　to　system　operation.　To　address　this　issue,　an　interval　small-signal　stability　analysis　approach　is　proposed　to　investigate　the　system　stability　under　multiparameter　uncertainty.　First,　the　interval　state-space　model　of　the　grid-connected　VSC　system　is　constructed　based　on　interval　symbolic　linearisation.　Furthermore,　the　interval　eigenvalue　decomposition　is　introduced　to　calculate　the　interval　eigenvalue　distribution　of　the　interval　state-space　model.　Eventually,　the　upper　bounds　of　the　real　part　of　the　dominant　interval　eigenvalues　are　utilised　for　deriving　interval　stable　parameter　regions.　Results　of　Monte　Carlo　analysis　and　time-domain　simulations　of　the　grid-connected　VSC　system　are　utilised　to　verify　the　effectiveness　of　the　proposed　interval　stability　analysis　method.