An improved portable folding table includes a folding frame and a table top supported by the folding frame. The folding frame includes a connecting sleeve, supporting blocks, supporting rods coupled to the connecting sleeve and the supporting blocks and first/second cross-bars coupled to the supporting blocks. The table top includes a tablecloth, third/fourth cross-bars at the bottom of the tablecloth and coupled to the supporting blocks, auxiliary cross-bars positioned between the third and fourth cross-bars and holders fixedly attached to the bottom of the tablecloth to receive ends of the auxiliary cross-bars. The holders prevent the auxiliary cross-bars from sliding out during normal operation.