In this work, we tentatively assign the charmed mesons DJ ( 2771.7 ± 1.7 ± 3.8 66.7 ± 6.6 ± 10.5 2763.3 ± 2.3 ± 2.3 60.9 ± 5.1 ± 3.6. The BaBar collaboration also analyzed the helicity distributions to determine the spin-parity, and tentatively identified the (D(2550),D(2600)) as the 2S doublet (0 − , 1 − ), the D(2750) and D(2760) as the D-wave states. The relevant parameters are presented in Table II, where we also present the possible correspondences among the particles observed by the LHCb and BaBar collaborations. The physicists have also studied the decay behaviors of these charmed mesons using the The heavy meson effective theory is a powerful tool in studying the properties of hadrons with a single heavy quark. With this method, P. Colangelo et al. proposed a classification of many observed cq and bq mesons in doublets [6]. In Ref.[7], we study the strong decays of the charmed mesons3000) and D * J (3000) with the heavy meson effective theory in the leading order approximation. And the ratios among decay widths of different channels were calculated. But the exact value of the decay widths were not given out, which constitutes the first motivation of our study. The quark pair creation (QPC) model is another effective method to 3 study the strong decays of the mesons, which is also known as the 3 P 0 decay model. 3000) and D * J (3000), it is necessary and interesting to systematically study the strong decays of these charmed mesons by the 3 P 0 decay model with the common oscillator parameter R.In the heavy quark limit, the heavy-light mesons Qq can be classified in doublets according to the total angular momentum of the light antiquark s l , s l = s q + L, where the s q and L are the spin and orbital angular momentum of the light antiquark, respectively [23]. In the case of the radial quantum number n = 1, the doublet (P ,P * ) have the spin-parity Jfor L = 0; the two doublets (P * 0 , P 1 ) and (P 1 , P * 2 ) have the spin-parity Jrespectively for L = 1; the two doublets (P * 1 , P 2 ) and (P 2 , P * 3 ) have the spin-parity J2 respectively for L = 2; the two doublets (P * 2 , P 3 ) and (P 3 , P * 4 ) have the spin-parity Jrespectively for L = 3, where the superscript P denotes the parity. The n = 2, 3, 4, states are clarified by analogous doublets, for example, n = 2, the doublet (P ′ , P * ′ ) have the spin-parity J0 have unnatural parity, and their possible spin-parity In the following, we list out the possible assignments,The article is arranged as follows: In section 2, the brief review of the 3 P 0 decay model is given (For the detailed review see Refs. [9,11,12,14]); In section 3, we study the strong decays of the charmed3000) with the 3 P 0 decay model;In section 4, we present our conclusions. The main assumption of the 3 P 0 decay model is that the strong decays take place via the creation of a 3 P 0 quark-antiquark pair from the vacuum. The new produced quark-antiquark pair, together with the qq in the initial meson, regroups into two outgoing mesons in all possible quark rearrangement ways,...