J Lo showed off her stunning bod with these pics over the weekend ... schooling the Instagram world how to truly execute poolside pics. The peachy swimwear perfectly wrapping around her flawless body is also another reminder of why she's always working out ... even on vacation.

Jennifer clearly had one thing in mind -- her captions and hashtags on the pic were definitely themed: "Everything's just peachy" and added "#tangerinedream #peachesNCream #topnaughty #suitsandfruits #throwingshades #doublebuns."

Goodness gracious.

J Lo will be wrapping up her Las Vegas residency later this month at Planet Hollywood ... so, the pics are a great promo for her big finish.

We're guessing Vegas feels very much like A-Rod does -- hate to see her go, but love watching her leave.