Rapin's written works were intimately linked to his public life and the political situation of France, as well as the humanist sensibility of the age. Rapin was close to many writers of the period, including Joseph Justus Scaliger, Jacques-Auguste de Thou, Etienne Pasquier, Jacques Gillot and Agrippa d'Aubigné.
His written works span the genres and forms of the period. He wrote French translations of Ariosto (Canto 28 of the Orlando Furioso, 1572), Cicero, Ovid, Martial, Horace, 7 Psalms (VII Psaumes Pénitentielles), and of many Neo-Latin poets (Michel de L'Hospital, Grotius, Théodore de Bèze, Scaliger, Jacques-Auguste de Thou); he wrote Latin works as well. He contributed to the funeral poem anthologies (or "tombeaux") for Pierre de Ronsard, Philippe Desportes, Claude Dupuy and others.
Rapin's poetry used the "vers mesuré" system of Jean-Antoine de Baïf (an attempt to write French poetry based on long and short syllables like ancient Greek or Latin), but modified the system to permit traditional French poetic elements (including rhyme). His love poetry is at times anti-petrarchian and satirical (contribution to La Puce de Ma Dame des Roches; La Douche), and at times idealized and Neoplatonic (L'Amour philosophe). He also wrote eclogues praising the country life, as in Horace (Les Plaisirs du gentilhomme champestre, 1575 and Elegie Patorale pour un Adieu, 1581-3), epitaphs on war (Le Siège de Poitiers) and occasional verse of consolation, victory and other matters. His satirical vein is most apparent in his contributions to the Satire Ménippée (1593/1594) which railed against the Holy League.
Finally, his will and the 30 letters by Rapin that have survived are important documents of late-Renaissance humanism in France.