The objective of the present study was to reveal different tolerance of peanut plants to Ca deficiency by determining Ca uptake and Fourier transform infrared spectral (FTIR) differences of two peanut cultivars grown in nutrition solution. Peanut cultivars LH11 and YZ9102 were selected. Seedlings at the first leaf stage were cultivated for 28 days in nutrient solution with 0, 0.01 and 2.0 mmol·L-1 Ca treatments, respectively. The results showed that under 0 and 0.01 mmol·L-1 Ca supply, YZ9102 did not show Ca deficiency symptoms and the plant biomass did not change, whereas LH11 exhibited shoot-tip necrosis, smaller plant size, more lateral branches, and plant dry matter weights decreased significantly. YZ9102 had higher plant Ca concentration and Ca accumulation than LH11. Besides, for LH11, Ca was mainly accumulated in roots, while for YZ9102 mainly in leaves. As compared with plants cultivated in 2.0 mol·L-1 Ca nutrition, root, stem and leaf of LH11 plants under Ca deficiency stress showed higher transmittance at peaks 1 060, 1 380, 1 655, 2 922, and 3 420 cm-1 in FTIR spectra, indicating that the contents of protein, sugar and lipid decreased obviously in LH11 plants in condition that Ca supply was limited. However, the FTIR spectra of YZ9102 were less affected by Ca deficiency. It is suggested that YZ9102 might be more tolerant to Ca deficiency.